# Problems with Steel



## Roskrow (Aug 26, 2020)

I have never tried to post a new thread in HMEM so just hope this is read.

I have recently needed to drill small holes (5/16th) in Mild Steel. But I have found that although almost all drill with ease I have recently had a number of holes that just will not allow the drill to penetrate. I think I have totally ruined some 5 or 6 drill bits.

Is the problem poor quality steel or is it just me ? 
Any assistance in giving me a solutioin would be greatfully received


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## Cogsy (Aug 26, 2020)

Sounds like you're either trying to drill something that is too hard for the drill bits, or your drilling technique is work hardening whatever material you're trying to drill (some materials work harden a lot easier than others). The final option, and a mistake I have made once or twice, is managing to run the mill/drill backwards which never works.


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## Roskrow (Aug 26, 2020)

Thanks, I hear what you say, but if you are grilling 2 foles adjacent to each other, with a long pause between each I just do not understand why hole A drills easily, and hole be will not. to the extent of totally ruining the drill bit.
 I have a friend who has just had the same exoerience (he is a trained engineer). He needed to drill 3 holes in part of a garage door. holes 1 and 2 no problem. but hole 3 +was so hard that even a cobalt drill found it hard going. 
His opinion is that the scrap yards that remit scrap to India are not careful in their sorting, which means when the scrapis re-melted it is muddled up with various grades


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## Roskrow (Aug 26, 2020)

Cogsy, I have just noticed that you live in WA. I was there from 1962 to mid 1970, i was in Real Estate. Amongst many other propertie i for a perion owned Bay View Mansions in Claremont. Whre do you live and what do you do, or did do ?
Best wishes Malcolm Farrant (Roskrow)


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## SmithDoor (Aug 26, 2020)

Sounds like bad drill bits.
They made drill bits for wood that just not last. 
I have a package of drill bits from 1950's that will not drill steel.

Dave



Roskrow said:


> I have never tried to post a new thread in HMEM so just hope this is read.
> 
> I have recently needed to drill small holes (5/16th) in Mild Steel. But I have found that although almost all drill with ease I have recently had a number of holes that just will not allow the drill to penetrate. I think I have totally ruined some 5 or 6 drill bits.
> 
> ...


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## cheepo45 (Aug 26, 2020)

Drill with a smaller drill first, slow the drill RPM down, and use some oil-should work fine.
 Scott


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## Tim Wescott (Aug 26, 2020)

It depends on where you're sourcing your steel.  My dad once found a ball bearing embedded in some "mild steel" 2 x 2 x 1/4 inch angle iron.  It was only slightly deformed, and had clearly survived whatever remelt was done when the mill turned some scrap into some angle iron.

It ruined a nice saw blade, too.

This was 20 or 30 years ago, but I doubt things have changed.


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## IanN (Aug 26, 2020)

Roskrow said:


> I have never tried to post a new thread in HMEM so just hope this is read.
> 
> I have recently needed to drill small holes (5/16th) in Mild Steel. But I have found that although almost all drill with ease I have recently had a number of holes that just will not allow the drill to penetrate. I think I have totally ruined some 5 or 6 drill bits.
> 
> ...



Hi,

What are you using for cutting fluid?

Ian


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## SmithDoor (Aug 26, 2020)

I have worked over 40 years in steel. We drill thousands without cutting oil in A36 steel.
If has problem it was drill bit.

Dave




IanN said:


> Hi,
> What are you using for cutting fluid?
> 
> Ian


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## TonyM (Aug 27, 2020)

Are you feeding by hand? It may be that the drill is being damged breaking through. If the bit snatches at the end check the tip before trying to drill the next hole.


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## Ozwes007 (Aug 27, 2020)

Another issue we have had at work is Chinese steel having hard spots in it. You see them when you are machining and when drilling or milling. Mild steel and 1020 grades are the worst for it.


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## johwen (Aug 27, 2020)

Can You send a photo of the cutting end of the drill before you start drilling and after the drill has refused to cut and we may be able to determine the answer to the problem? Are they new drills or have they been sharpened before use?


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## Richard Hed (Aug 27, 2020)

Roskrow said:


> Thanks, I hear what you say, but if you are grilling 2 foles adjacent to each other, with a long pause between each I just do not understand why hole A drills easily, and hole be will not. to the extent of totally ruining the drill bit.
> I have a friend who has just had the same exoerience (he is a trained engineer). He needed to drill 3 holes in part of a garage door. holes 1 and 2 no problem. but hole 3 +was so hard that even a cobalt drill found it hard going.
> His opinion is that the scrap yards that remit scrap to India are not careful in their sorting, which means when the scrapis re-melted it is muddled up with various grades


I workt for a place that bought metal sheets from Maylaysia.  The Steel was not properly melted and we would actually find bolts sticking out of the sheets that were partially melted.  The bolts, of course, were a different grade with different alloys and etc.


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## Gabe J DiMarino (Aug 27, 2020)

If your drilling mystery metal , I would pre -drill and use an appropriate rpm for the size drill then try with a sharpened 5/16 drill and some lube. The larger the drill the slower your rpm should be.


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## davidyat (Aug 27, 2020)

*I went through the same problem a while back. My mentor asked me what I was doing. He found out that I was drilling a small hole TOO slowly and was getting "work hardening". When I started to drill with a faster hand input, it drilled very easily.
Grasshopper*


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## William May (Aug 27, 2020)

I avoid all mystery metal. When someone offers me some steel, I usually tell them that I have all I need of that particular material. It is much cheaper and faster in the long run to buy a known piece of steel to a spec, and then machine it. I still have some metal stored in my garage that someone gave me, that is nasty in every way. It is very difficult to machine, hard to drill, etc, etc. In fact, I'm glad you reminded me of it, because it is going into the semi-annual bulky trash pickup this year.  
The situation is different if you have to work on an existing part.  I would slow the drill down, use a good quality drill bit and cutting oil, and see what happens. If the material is thick, or the hole is large diameter, drill a pilot hole first. 
If you buy scrap metal to machine. you will find you are generating a lot of scrap metal, too.


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## L98fiero (Aug 27, 2020)

davidyat said:


> *I went through the same problem a while back. My mentor asked me what I was doing. He found out that I was drilling a small hole TOO slowly and was getting "work hardening". When I started to drill with a faster hand input, it drilled very easily.
> Grasshopper*


That's probably the key, when drilling with a hand drill the speed is often too high or the feed too low or both and the drill gets dulled, then when you try to drill the next hole it work hardens the bottom of the hole so even a new drill is difficult to start.
Stainless in particular is an issue, slow speed and fast feed and a cutting fluid is the way to go and don't let the drill rub, it work hardens and then it's difficult to get the drill started cutting again. I had someone try to drill a 5/16 hole on 304 stainless at 750 RPM and the cutting edges broke down and left particles in the stainless. The drill didn't stick in the hole but there was no finishing that hole to depth, throw it away and try again, this time the right speed and feed.


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## willray (Aug 27, 2020)

Roskrow said:


> I have recently needed to drill small holes (5/16th) in Mild Steel. But I have found that although almost all drill with ease I have recently had a number of holes that just will not allow the drill to penetrate. I think I have totally ruined some 5 or 6 drill bits.
> 
> Is the problem poor quality steel or is it just me ?



You need to tell us what you're actually drilling, what you're drilling with, and what kind of holes you're drilling.

"Mild steel" - if it's really mild steel and of any reasonable quality - really won't harden much, almost nomatter what you do to it.

"Mild steel" as found in mystery-metal chunks of various already-existing implements, like bed frames and other structural bits that manufacturers use as parts of their products, can be just about anything, and of wildly varying composition from chunk to chunk, or even from spot to spot on the same piece. As has been mentioned by previous posters, the same problem exists in "Mild steel" from less-reputable reprocessors (gone are the days of quality fresh "new" steel straight from the ore, as was produced by USS/etc back when first-world countries actually made things rather than ordering them from China).

Likewise, what variety of drill bit, and how you're driving it, make a huge difference in the drillability of 5/16ths holes.

With a drill press, and a decent quality HSS bit, you should be able to put tens to hundreds of 5/16ths holes in real mild steel, without coolant, and without drilling a pilot hole.  More, if you're drilling blind holes.

Try doing 5/16 thru-holes with a hand-drill in mystery-metal "mild steel", pilot-hole or no, and like as not, you'll hit a hard bit of skin coming out of the far side, wobble the drill motor because of the change in torque, and rip a lip off the bit.  Fail to notice that, and your next hole goes to crap.

Try doing any of this with less-than-quality bits, and all bets are off.  You may get 200 perfect holes, or you may get 2 decent holes and then for no detectable reason the thing turns into a noodle in the chuck.  Buy your bits from Hobo-fright, TSC, or cheap stuff from Amazoon, and you'll be reasonably lucky if all of the drills are actually "sharpened" such that the cutting edge contacts the material before the relief behind it.  Surprisingly, if you're ham-handed enough even with those potato-mashers, and you happen to have lucked into one of the hard ones, with a drill-press it will sometimes "drill" for a while by turning the metal underneath it into pudding and pushing it out of the way.  Eventually you soften the tip of the bit enough that that stops working too.

So - more information - maybe a photo of the holes you've drilled (front and back), and photos of the damaged drill bits, and then hopefully give you some help that's not just guesses!


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## Cogsy (Aug 27, 2020)

Roskrow said:


> Cogsy, I have just noticed that you live in WA. I was there from 1962 to mid 1970, i was in Real Estate. Amongst many other propertie i for a perion owned Bay View Mansions in Claremont. Whre do you live and what do you do, or did do ?
> Best wishes Malcolm Farrant (Roskrow)


I live in the foothills in the Armadale area - a long way from the expense of Claremont. I'm still working (I'm only mid 40's) as a research physicist currently. Not good money but incredibly interesting (to me anyway).


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## SmithDoor (Aug 27, 2020)

A photo may help.
Odds are it is the drill bit.
Even if it is a harder steel the drill bit would do job.
They have made past low cost drill bits they look just like a good drill bit. But they will not drill steel.
At one time in my life I was buying drill bits gross at one and found a great price was bad drill bits. 
Most drill bits die to the person drilling the hole.
Did have that lasted till we could not sharpen the drill aka to stub.
The steel that we drilling was grade 45 it is harder than A36. 

Dave



johwen said:


> Can You send a photo of the cutting end of the drill before you start drilling and after the drill has refused to cut and we may be able to determine the answer to the problem? Are they new drills or have they been sharpened before use?


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## clockworkcheval (Aug 27, 2020)

Of course I concur with all common sense comments mentioned above. However sometimes you have no choice in the material you have to drill and it won't work with HSS. What oftentimes helps is to take a concrete drill, which has a carbide tip. The smallest size I can get is 3 mm (about 1/8th). This I grind as a steel drill. I use it as a starter for though materials (also for hard skins of cast iron) with a lot of pressure, feed, cutting oil and moderate speed. In most cases it will get me a reasonable starter hole which I can then follow up with regular HSS drills.


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## comstock-friend (Aug 27, 2020)

Check feeds and speeds for the size drill you use (just about all my holes are drilled on the Bridgeport, my import drill press is generally much too fast). Avoid cheap Chinese and Indian drills. Do not expect things like angle iron taken from bed frames to be 'mild steel'. Material with a pedigree is the way to go, A36 hot rolled, 1018 cold rolled at a minimum (or UK or ISO equivalents). I'm hard pressed to use anything other than free machining leaded steel or 1144 stress proof for good surface finish, strength, etc (or drill rod=silver steel). 

John


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## OrangeAlpine (Aug 28, 2020)

The problem with drilling closely spaced holes sounds like the steel is hardening from heat generated from drilling the previous holes.  This is real easy to do with air hardening steel or sometimes with low quality steel made from anybodies guess feed stock.  Lately I've become a real fan of low rpm, high pressure drilling.  Seems to avoid a lot of problems.
Bill


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## Gabe J DiMarino (Aug 28, 2020)

You can pretty much tell what it is by spark testing and the type of chips its makes . After cutting metal for 35 years you just know.


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## gunner312 (Aug 29, 2020)

Roskrow said:


> Thanks, I hear what you say, but if you are grilling 2 foles adjacent to each other, with a long pause between each I just do not understand why hole A drills easily, and hole be will not. to the extent of totally ruining the drill bit.
> I have a friend who has just had the same exoerience (he is a trained engineer). He needed to drill 3 holes in part of a garage door. holes 1 and 2 no problem. but hole 3 +was so hard that even a cobalt drill found it hard going.
> His opinion is that the scrap yards that remit scrap to India are not careful in their sorting, which means when the scrapis re-melted it is muddled up with various grades


IMHO, after 30+ years as a Machinist, I have found that most of the time drilling problems are caused by, 1 drilling too fast, 2 drilling with a dull drill bit. 3 not using drill lube. AND again pushing the drill to fast/hard. Use your speeds and feeds, drill slower and with less pressure. Let the drill do the work and SHARPEN YOUR DRILL BIT!!.


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## terryd (Aug 30, 2020)

gunner312 said:


> IMHO, after 30+ years as a Machinist, I have found that most of the time drilling problems are caused by, 1 drilling too fast, 2 drilling with a dull drill bit. 3 not using drill lube. AND again pushing the drill to fast/hard. Use your speeds and feeds, drill slower and with less pressure. Let the drill do the work and SHARPEN YOUR DRILL BIT!!.




Using too little pressure can also cause problems.  The drill can then rub which causes it to overheat and lose it's edge.  Unless you calculate speed/feed rates (assuming of course a sharp drill) it is a matter of 'feel' which I developed in my 50+ years of experience,

Best regards,

TerryD


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## Roskrow (Aug 30, 2020)

You have all sent me very helpful suggestions, for which I thank you. Alas I have now throne away the ruined bits, I think the comments on over hear and gardening are very relevent.
For 5/16 I was dril


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## Roskrow (Aug 30, 2020)

I would like to say a BIG thank you to so many of you who have tried to assist me.

It seems the errors are almost certainly caused by myself. 

I am 83, and I confess not an exprienced lathe etc user, but I do learn from my many errors !!

I try and purchase really good quality drill bits, but no,I do not re-sharpen them. 

It seems I need to learn what speed I should be drilling. I seldom need holes any bigger that 1/2 inch. Perhaps there is a chart somewhere that would guide me.

Again many many thanks for all your wise words.
Malcolm arrant


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## goldstar31 (Aug 30, 2020)

Perhaps Tubal Cain's book 'Drills, Taps and Dies' would be of use.

I've no idea of the price now because mine is on file now.

When one gets to 90, one gets cluttered with things.

Actually my son is in quarantine from a visit to France and wants to buy and re-build a Deux Chevaux and I said that he should learn to plug weld onn my little Mig.  Lots of holes.

Take care


Norman


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## gunner312 (Aug 30, 2020)

terryd said:


> Using too little pressure can also cause problems.  The drill can then rub which causes it to overheat and lose it's edge.  Unless you calculate speed/feed rates (assuming of course a sharp drill) it is a matter of 'feel' which I developed in my 50+ years of experience,
> 
> Best regards,
> 
> TerryD


Yes that's true, but using too much pressure causes more wear on the drill margins and dulls the drill quickly.  Also can cause the point to "walk".


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## gunner312 (Aug 30, 2020)

Roskrow said:


> I would like to say a BIG thank you to so many of you who have tried to assist me.
> 
> It seems the errors are almost certainly caused by myself.
> 
> ...


 Malcolm, 

You really should learn to sharpen your drills, it's really a very easy skill to learn.  I have a Darex drill sharpener that I bought 20 years ago and I am sure that it has saved me its cost many times over. However, before I bought it I sharpened my drill bits by hand and eye. I still do on occasion (when I'm too lazy to set up the drill sharpener). There are inexpensive drill sharpener attachments for your shop bench grinder that are readily available and can save you time and money. I am 74 and still making models and toys as my wife calls what I make.


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## kwoodhands (Aug 30, 2020)

davidyat said:


> *I went through the same problem a while back. My mentor asked me what I was doing. He found out that I was drilling a small hole TOO slowly and was getting "work hardening". When I started to drill with a faster hand input, it drilled very easily.
> Grasshopper*



I agree, I had a problem with  a steel plate that needed 16  3/8" holes in a close circular pattern. I got thru the first plate but wasn't easy. My mothers side of the family are machinists. I gave a cousin a call.
 He said I may have been work hardening the plate. He suggested that I drill 4 holes opposite each other. Then 4 more opposite each other.  Repeat til the 16 holes are complete, This lessens the chance of work hardening because the heat from drilling has a chance to cool. 
If the holes were spaced further apart then this may not be necessary.
Tom's suggestion worked. I actually tested his theory on the last of 8 plates by trying to drill the first two holes close together. Drilling went hard like I expected. Finished drilling Tom's way, no problems.
I used plumbers cutting oil, the dark stuff and Cleveland brand drills.
mike


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## SmithDoor (Aug 30, 2020)

Photo of poor drill bits
They just like any other drill bits. But try drilling steel they will fail.
About the only thing this group drills can drill is pine wood. 
Only have them as reminder of bad drill bits.

Dave


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## goldstar31 (Aug 30, 2020)

After reading the many comments and then my own and think.  I am. a guy with 3" division plates with rows and rows of holes
Two comments have to emerge.  Mine have been drilled in free cutting mild steel and the holes and those are drilled with stub drills.

Writing as a 'none engineer, we seem to have forgotten that a drilling machine, a mill and a lathe are cutting in a circular pattern with similar tools------ but to get anywhere the cutting speeds of all of them have to be adjusted for the Diameter of the drill as well s the material.
Quite simply- IMHO, we drill too fast into cheap jack metal with equally cheap jack drills------and naturally, belly ache. 
Again, no one has deigned to mention the old Slocombe drills/centre drills.

I had a daft one the other day.  I was drilling a 7mm hole into an 38mm/1.5" lump.  It ended up as a rattling fit and two points arose.  The first was a worn out drill chuck and the lips of the drill being unequal.

 My thoughts , good folks, but I bought TWO precision drill chucks------ and thoughts about boring with a properly fashioned boring bit- instead.

My musings-- of course


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## terryd (Aug 31, 2020)

Roskrow said:


> I have never tried to post a new thread in HMEM so just hope this is read.
> 
> I have recently needed to drill small holes (5/16th) in Mild Steel. But I have found that although almost all drill with ease I have recently had a number of holes that just will not allow the drill to penetrate. I think I have totally ruined some 5 or 6 drill bits.
> 
> ...




Hi,

Probably trying to teach my grandmother to suck eggs but here goes - Always start with a centre punch mark, this not only locates the hole but gives a place for the 'land' of the drill (the inevitable flat across the end of the drill between the flutes) which allows the cutting edges to start cutting.  If you try to cut too slowly or too fast (too little or too much pressure on the drill) the 'land' will rub on the work and overheat as it cannot do any cutting.  

After centre punching I suggest that you drill a pilot hole big enough to accommodate the 'land' of the 5/16" drill, this allows the cutting edges to do their work without any rubbing,  Keep a steady pressure on the drill - enough to keep it cutting and no more.  I use my drills mostly dry these days as I'm now in it for a hobby but in industry and school workshops we used a cutting fluid but HSS drills - which are the only ones I use - don't really need it in mild steel.  I have a set of HSS drills from 0.5 to 10 mm x 0.1mm i.e. 100+ drills.  I've had these for almost a decade and only had to replace a few small drills through breakage (or loss!!) and one 3.2 mm drill lost it's edge.  When dull I hand sharpen which I learned to do almost 60 years ago.  I now use 4 facet sharpening and thin the web to reduce the 'land' on the larger drills.

TerryD


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## terryd (Aug 31, 2020)

goldstar31 said:


> After reading the many comments and then my own and think.  I am. a guy with 3" division plates with rows and rows of holes
> Two comments have to emerge.  Mine have been drilled in free cutting mild steel and the holes and those are drilled with stub drills.
> 
> Writing as a 'none engineer, we seem to have forgotten that a drilling machine, a mill and a lathe are cutting in a circular pattern with similar tools------ but to get anywhere the cutting speeds of all of them have to be adjusted for the Diameter of the drill as well s the material.
> ...



Hi goldstar,

 I no longer use Slocomb drills for anything other than on the lathe when intending to turn between centres  Instead I use spot drills.  I was recommended to these by the late John Stevenson when I used to correspond with him.  They are excellent and have much smaller lands than Slocomb drills.

TerryD


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## goldstar31 (Aug 31, 2020)

terryd said:


> Hi goldstar,
> 
> I no longer use Slocomb drills for anything other than on the lathe when intending to turn between centres  Instead I use spot drills.  I was recommended to these by the late John Stevenson when I used to correspond with him.  They are excellent and have much smaller lands than Slocomb drills.
> 
> TerryD



I take and appreciate your remarks -- and of course Sir John's- RIP.

I think that I'm somewhat old fashioned-- the understatement of the decade.

I have quite a lot of the things- and being Scots and born on the steps of the synagogue, retained the bag of sweets on our engagement, keeping them for the children. They in their turn- well you know the rest.

My son still has the claw hammer which my father made on the anvil- before WW2-- and I have my late wife's Mickey Mouse gas mask and my father in laws service respirator and tin hat.  You never know when things like that will be needed.
I'm still wearing a solid gold Waltham gents fob watch which had never run since 1938-- or before.
I'm careful-- not mean.
Regards

N


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## terryd (Aug 31, 2020)

Hi Goldstar,

Like you as an old timer, I also usedtools which had been passed down to me from father and grandfather.  but unfortunately I had a devastating garage/workshop fire which destroyed all of my tools and machinesas well as my sailing dinghy and 2 Triumph Stags one of which I was rebuilding.  So as you see I had to re equip after rebuilding, fortunately I had very good insurance which was some compensation and was able to completely replace almost everything.  The main road past my bungalow linking to the M1 was blocked for 4 hours by 2 of the three fire appliances which attended.  I alsways reccomend that folks check their insurance policy as some only offer small amounts for contents of detached buildings, around 2 -5000 pounds whereas mine included full replacement costs.  Was I glad that I hadn't gone for those 'cheaper home insurance' offers.

My own old gold watch passed down from my grandfather (a Benson, a present when he retired) is still working and I wear it occasionally to remind me of him in place of my own Rolex.







The bottom left picture is the remains of a Boxford CSB on stand with splashback.

TerryD


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## goldstar31 (Aug 31, 2020)

I can sympathise with your loss as my wife died without warning almost 5 years ago on September 4th.
The rest was unimportant in comparison

So Best wishes

Norman


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## L98fiero (Aug 31, 2020)

terryd said:


> I no longer use Slocombe drills for anything other than on the lathe when intending to turn between centres  Instead I use spot drills.  I was recommended to these by the late John Stevenson when I used to correspond with him.  They are excellent and have much smaller lands than Slocombe drills.


Another point about the spotting drills, use 135 or 145 degree instead of the 90 degree spot drills, they center the drill better. When you use the 90 degree spot drill you get the same problems as with the combined drill and countersink(center drill/Slocombe) in that there is no support from the chisel edge/point of the drill and you can get chatter and an out of round and oversize hole at the start.
Another side note is how to drill a ROUND hole in sheet metal. Often, when you drill sheet metal the hole will come out almost triangular, a way to prevent that is to put a small patch of cloth under the drill, it should be 2 or 3 layers thick depending on the cloth, and drill through that. When it was shown to me there was no rationale behind it just that it worked but I think the idea is that it supports the drill point as it goes through the sheet.


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## willray (Aug 31, 2020)

terryd said:


> I no longer use Slocomb drills for anything other than on the lathe when intending to turn between centres  Instead I use spot drills.  I was recommended to these by the late John Stevenson when I used to correspond with him.  *They are excellent and have much smaller lands than Slocomb drills.*



Before everyone starts misusing "Land" as the term to for the chisel edge on the web of a drill bit, please:

Viking Drill Bits : Drill Terminology

The land is the non-cutting space between the flutes - bassackwards of the structure of firearms-rifling (though consistent with "the land is the stuff that wasn't cut away).

As an aside, Viking drill bits seem pretty decent for the money.


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## L98fiero (Aug 31, 2020)

willray said:


> Before everyone starts misusing "Land" as the term to for the chisel edge on the web of a drill bit, please:
> 
> The land is the non-cutting space between the flutes - bassackwards of the structure of firearms-rifling (though consistent with "the land is the stuff that wasn't cut away).


The Viking definition of the land is a bit ambiguous, Kennametal-Greenfield has a better one, or not. So how wide is the land on their drills? Seems they've also called the margin, the narrow cylindrical area behind the leading edge of the flute, the land.


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## SmithDoor (Aug 31, 2020)

Sad to see.
I hope everyone is ok.

Dave



terryd said:


> Hi Goldstar,
> 
> Like you as an old timer, I also usedtools which had been passed down to me from father and grandfather.  but unfortunately I had a devastating garage/workshop fire which destroyed all of my tools and machinesas well as my sailing dinghy and 2 Triumph Stags one of which I was rebuilding.  So as you see I had to re equip after rebuilding, fortunately I had very good insurance which was some compensation and was able to completely replace almost everything.  The main road past my bungalow linking to the M1 was blocked for 4 hours by 2 of the three fire appliances which attended.  I alsways reccomend that folks check their insurance policy as some only offer small amounts for contents of detached buildings, around 2 -5000 pounds whereas mine included full replacement costs.  Was I glad that I hadn't gone for those 'cheaper home insurance' offers.
> 
> ...


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## willray (Aug 31, 2020)

terryd said:


> Like you as an old timer, I also used tools which had been passed down to me from father and grandfather.  but unfortunately I had a devastating garage/workshop fire which destroyed all of my tools and machinesas well as my sailing dinghy and 2 Triumph Stags one of which I was rebuilding...



I feel and share your pain:








Yes, that was the 30-inch model.

Fires suck.  Don't do it.


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## L98fiero (Aug 31, 2020)

willray said:


> I feel and share your pain:
> 
> Fires suck.  Don't do it.


Did you find out the cause of the fires?


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## Tim Wescott (Aug 31, 2020)

L98fiero said:


> Another side note is how to drill a ROUND hole in sheet metal. Often, when you drill sheet metal the hole will come out almost triangular, a way to prevent that is to put a small patch of cloth under the drill, it should be 2 or 3 layers thick depending on the cloth, and drill through that. When it was shown to me there was no rationale behind it just that it worked but I think the idea is that it supports the drill point as it goes through the sheet.



Inneresting.  I discovered by accident that if I back up a piece of sheet metal with a piece of wood on the drill press, I get a nice round hole.

In fact, it's so accidental that I only just now realized that's why my holes come out nicer on a drillpress than when I'm drilling freehand!


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## willray (Aug 31, 2020)

L98fiero]
Another side note is how to drill a ROUND hole in sheet metal. Often said:


> Inneresting.  I discovered by accident that if I back up a piece of sheet metal with a piece of wood on the drill press, I get a nice round hole.



The reason that you get non-round (roughly reuleaux-triange shaped, actually) holes when you try to drill sheet metal with a 2-flute drill, is because it's energetically favorable for one cutting lip to "dig in" and stop, while the other cutting lip pivots around the stationary one, cutting a 2x-drill-diameter arc, as compared to both cutting lips to cut at the same time.  The moving lip then catches and the formerly stationary lip starts cutting, and the drill walks around a 3-lobed path, alternately sticking and cutting.

The reason that drilling into a piece of wood (or at least a reasonably solid one) creates rounder holes, is because the drill is no-longer supported at "only one point" along the length of the flute - even if one lip tries to dig in to the wood, that flute describes some portion of a spiral along its length into the wood, so it does not form a distinct pivot point like the drill biting into sheet metal does.

One working hypothesis about the "use a bit of cloth between the drill and sheet metal" process, is that the cloth naturally wedges itself into the flutes, filling them up and limiting the depth of chip that each cutting lip can grab - kind of like the action of rakers on a chainsaw chain.


----------



## SmithDoor (Aug 31, 2020)

That was great lathe.
If I had I would rebuild it back to life.

I have done rebuild from machine tools to engines fire to floods. The worst is flood I had take everything apart. Sand was in ever nock and cranny

Dave



willray said:


> I feel and share your pain:
> 
> View attachment 118989
> View attachment 118990
> ...


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## Hrcoleman66 (Aug 31, 2020)

My late father, many years ago, was modifying a small box trailer to carry a small dinghy.  He went to the local hardware three times to buy the same drill bit because he was convinced that the sheet steel of the mudguard had a hard spot and he was blunting the drill.  Eventually, he asked me to have a look.  The first thing I did was to check that he had the drill running the right way.  Of course he'd had it running backwards.

But seriously, how small are th holes you are trying to drill?  Are you 'Pecking" to allow the chips to break and evacuate from the hole as the drill progresses?  Because if you are not, the chips will jam in the flutes of the drill, create friction and over heat the drill.

I doubt that it's the fault of the steel.  Even "cheap chinese" steel as others have called it, is not that bad.  India made steel maybe...

Cheers,

Hugh


----------



## IanN (Sep 1, 2020)

SmithDoor said:


> I have worked over 40 years in steel. We drill thousands without cutting oil in A36 steel.
> If has problem it was drill bit.
> 
> Dave


Hi Dave,

I realise that you have already decided that I am wrong, but just give it a go - try using cutting fluid

Al the best,
Ian


----------



## IanN (Sep 1, 2020)

gunner312 said:


> Yes that's true, but using too much pressure causes more wear on the drill margins and dulls the drill quickly.  Also can cause the point to "walk".



Hi,

In the Cain/Walshaw book "Drills, taps and dies" referred to by Norman there is an interesting set of notes (in Appendix A in my copy of the book) regarding some measurements of drilling feed forces made by Walshaw.

Not directly relevant to this point, but useful insight and worth a look

Ian


----------



## IanN (Sep 1, 2020)

terryd said:


> :
> Always start with a centre punch mark,
> :
> 
> ...



Hi Terry,

Second point first - four facet drills - I agree 100%.  The best aspect of the four facet form is that the chisel point of the normal twist drill is changed to a true point and so there is no need for the use of a centre punch

Your first point ("Always start with a centre punch Mark") I would qualify by adding "if accuracy is not important"

All these things are relative, of course, but the centre punch is the work of the Devil and the tool of the blacksmith - it has no place in precision work.  Think of the sequence followed when marking, centre punching and drilling a precisely located hole:

Step one)  Mark hole location - there will obviously be a tolerance/error in the measurements and marking, so the marked location will not be the truly intended location of the hole.

Step two)  Locate centre punch in crossed scribed lines (which we know already have an error) and introduce Mr Hammer in to the equation.  There are three possible results:
1) The resulting punch mark will be perfectly placed on the line intersect.
2) The punch mark will be miss placed, but by an amazing stroke of luck the error in the dot location perfectly cancels the error in the marking out
3) The punch mark will be miss placed and add further error to the error in the scribed lines

Let's be honest - 1 and 2 will not happen and you now have a centre mark even further from the desired location.

Now the centre mark crater - this could in theory be a perfect conical depression, but in reality is asymmetrical and so will push the drill slightly off the punched centre.  Situations 1, 2 and 3 above apply again, and as a result the actual drilled hole location is even further away from its intended place.

Centre punching ok if you are drilling holes in gate hinges.

Al the best,
Ian


----------



## goldstar31 (Sep 1, 2020)

Sounds remarkably like George Thomas- Model Engineers Workshop Manual


----------



## GrahamJTaylor49 (Sep 2, 2020)

Talking about center punches being the tool of the devil and "Mr. Hammer" causing even more problems, has any one tried the
"Dankroy" optical center punch ?  I bought one at the Model Engineering show at Wembly Conference Centre many years ago
and have used it with terrific results ever since. Used as directed one cannot help but get a perfect center punch on the scribed lines.
Just make sure that the scribed lines are in the correct place.


----------



## goldstar31 (Sep 2, 2020)

GrahamJTaylor49 said:


> Talking about center punches being the tool of the devil and "Mr. Hammer" causing even more problems, has any one tried the
> "Dankroy" optical center punch ?  I bought one at the Model Engineering show at Wembly Conference Centre many years ago
> and have used it with terrific results ever since. Used as directed one cannot help but get a perfect center punch on the scribed lines.
> Just make sure that the scribed lines are in the correct place.



I bought one - or similar at Harrogate- moons ago
I recall that there was  a free offer of re-pointing it


----------



## minh-thanh (Sep 2, 2020)

A little more of my experience :
I always use cutting fluid in steel and stainless steel drilling
At least with a little oil
I find it difficult to drill steel or especially stainless steel, mostly due to the heat generated during the drilling process  (If the drill bit, drilling speed, pressure ... is correct, the drilling still generates quite a lot of heat. )
  Maybe it's my habit, or feeling, I always use a little oil when drilling in aluminum and It seems that drilling is easier


----------



## clockworkcheval (Sep 2, 2020)

Two comments 1) for longer holes in tougher material like stainless I prefer 6 facet drills. You basically grind additional facets on the 'shoulder' at the outer diameter of the cutting edge, thereby relieving the forces on the hardest working part of the drill 2) for aluminium I always lubricate with something light like WD40 to prevent the build-up of a spot of aluminium on the cutting edge.


----------



## goldstar31 (Sep 2, 2020)

Heaven knows why but I don't but my son wants to restore a left hand Citroen Deux Chevaux.

Ok,  I did a English City and Guilds when I was a  Manure student and got distinctions and became a Certified Welder( note the Malapropism)! Ah well!
What I used to remove spot welds and to make a hole for 'plug welding' using my Mig welder was a spt welding removing drill.  They are pretty hard bits- and not unduly expensive.

Of course there is the usual prattle about work hardening  but today's -- or possibly yesterday's high strength alloyed steels  instead of the traditional phosphorus mild steel.  Of course these niobium steels did not work harden under the oxy acetylene torch but cracked.

Thoughts for the day? Well I DID say that I wasn't an engineer

Norman


----------



## ranger (Sep 2, 2020)

A few years ago, before I retired, I had to repair a stripped thread in a mild steel bracket. Drilling out to the next size up, M10 x M12, the tap felt as though it would break, drilling to maximum tapping size, new tap, threading compound, oil, nothing made any difference. My friend, a toolmaker gave me a pot of ‘cream’ his late mother had for a skin condition, ‘ e45’ I think?
I tried it,  it was like tapping into butter. I’ve used it for drilling and tapping threads into stainless steel as well. Apparently ‘Swarfega’ handcleaner works well for drilling into hard steel and stainless. I keep what’s left in the pot for machining operations in difficult materials.
Doug.


----------



## goldstar31 (Sep 2, 2020)

In all probability the 'cream'-- hand or face???? is  'lard oil'

I use refined lard oil as my cutting fluid

HTH


Norman


----------



## ranger (Sep 2, 2020)

Would ‘lard oil’ be used for skin cream? I think ‘e45’ is lanolin and paraffin based.Doug.


----------



## goldstar31 (Sep 2, 2020)

Lanolin-IFIRC is the 'suint' from a sweep's fleece.  'Paraffin' is a mineral  base whilst lard is the rendering of fat. I'm keeping out of things which resulted on the Indian Mutiny and  the Black Hole of Calcutta but refined lard oil and tallow( here we go again) are excellent for tapping and lard oil was what the old engineers  mixed for cutting fluids.
Here we go again, you get to the saponification of fatty acids which start resin technology-- and err hand soaps.
One thing that I  can tell you is using lard oil you end with nice soft hands.

Swarfega- I guess has glycerine in. Back to LOFA and paint technology.

Hey- mind you I'm neither engineer nor chemist but merely a 'retired 'bean counter'
Other people may hold different views. 

 I'm a  shareholder in a rather interesting pharmaceutical firm which had its origins in selling soap as liver pills. Seemingly there is a connection with conducting classical music

I'll get me coat


----------



## KellisRJ (Sep 2, 2020)

IanN said:


> Hi Terry,
> 
> Second point first - four facet drills - I agree 100%.  The best aspect of the four facet form is that the chisel point of the normal twist drill is changed to a true point and so there is no need for the use of a centre punch
> 
> ...


----------



## ranger (Sep 2, 2020)

goldstar31 said:


> Lanolin-IFIRC is the 'suint' from a sweep's fleece.  'Paraffin' is a mineral  base whilst lard is the rendering of fat. I'm keeping out of things which resulted on the Indian Mutiny and  the Black Hole of Calcutta but refined lard oil and tallow( here we go again) are excellent for tapping and lard oil was what the old engineers  mixed for cutting fluids.
> Here we go again, you get to the saponification of fatty acids which start resin technology-- and err hand soaps.
> One thing that I  can tell you is using lard oil you end with nice soft hands.
> 
> ...


‘Sweep’s fleece?


----------



## KellisRJ (Sep 2, 2020)

IanN said:


> Hi Terry,
> 
> Second point first - four facet drills - I agree 100%.  The best aspect of the four facet form is that the chisel point of the normal twist drill is changed to a true point and so there is no need for the use of a centre punch
> . . .


Ian, thanks for posting this and your four facet sharpening jig plans. As a new member I appriciate the information as sufficent to guide additional research. Your coment prompted me to do a search on four facet and now I have yet another project to make a tool so I can make something. I also noted Norman's comment on the similarity of the four facet grind and how endmills and slotdrills are ground. I made a very recent purchase of a Darex E-90 end mill sharpener. Though the stone is rather coarse looking, specification not provided in the factory liturature, and limited to Hardinge 5C collet sizes, I'm wondering if the 1/4" it came equiped with as a pilot would cover most needs . . .

Ron


----------



## goldstar31 (Sep 2, 2020)

ranger said:


> ‘Sweep’s fleece?



Bah! That is the problem being virtually blind in my left eye and having split vision in the other.

Called Macular Degeneration 

Thanks , perhaps there will never be another you?


----------



## holmes_ca (Sep 2, 2020)

willray said:


> The reason that you get non-round (roughly reuleaux-triange shaped, actually) holes when you try to drill sheet metal with a 2-flute drill, is because it's energetically favorable for one cutting lip to "dig in" and stop, while the other cutting lip pivots around the stationary one, cutting a 2x-drill-diameter arc, as compared to both cutting lips to cut at the same time.  The moving lip then catches and the formerly stationary lip starts cutting, and the drill walks around a 3-lobed path, alternately sticking and cutting.
> 
> The reason that drilling into a piece of wood (or at least a reasonably solid one) creates rounder holes, is because the drill is no-longer supported at "only one point" along the length of the flute - even if one lip tries to dig in to the wood, that flute describes some portion of a spiral along its length into the wood, so it does not form a distinct pivot point like the drill biting into sheet metal does.
> 
> One working hypothesis about the "use a bit of cloth between the drill and sheet metal" process, is that the cloth naturally wedges itself into the flutes, filling them up and limiting the depth of chip that each cutting lip can grab - kind of like the action of rakers on a chainsaw chain.



Willray, I have also used wood as a backing and before that, I have used a piece of cloth under the drill bit, I just fold a small piece into a small square place it between the metal and the drill bit,

Edmund...........Alberta


----------



## terryd (Sep 3, 2020)

goldstar31 said:


> Heaven knows why but I don't but my son wants to restore a left hand Citroen Deux Chevaux.
> 
> Ok,  I did a English City and Guilds when I was a  Manure student and got distinctions and became a Certified Welder( note the Malapropism)! Ah well!
> What I used to remove spot welds and to make a hole for 'plug welding' using my Mig welder was a spt welding removing drill.  They are pretty hard bits- and not unduly expensive.
> ...





ranger said:


> A few years ago, before I retired, I had to repair a stripped thread in a mild steel bracket. Drilling out to the next size up, M10 x M12, the tap felt as though it would break, drilling to maximum tapping size, new tap, threading compound, oil, nothing made any difference. My friend, a toolmaker gave me a pot of ‘cream’ his late mother had for a skin condition, ‘ e45’ I think?
> I tried it,  it was like tapping into butter. I’ve used it for drilling and tapping threads into stainless steel as well. Apparently ‘Swarfega’ handcleaner works well for drilling into hard steel and stainless. I keep what’s left in the pot for machining operations in difficult materials.
> Doug.


 
Hi Doug,

The toolmakers I worked with used naturall occuring lubricant when drilling small holes - spittle.

Hi Norman,

perhaps the malapropism explains all the BullSh**

TerryD


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## Steamchick (Sep 3, 2020)

E 45 is mostly Lanolin, I think? Lanolin is the natural grease made by sheep that keeps the fleece waterproof. My Aunt, a lifelong nurse, loved to find a bit of wolf in a hedge or on a fence and rub it on her hands, so the skin could benefit from the lanolin.
For thread cutting, I bought a pot of someone's elixir, only to find it was dentists' green denture/tooth polish! But really good for taps and dies, and the tough drilling task.
But the best remedy for any drilling difficulty is a sharp drill, correctly ground. And started with a machine located centre from using just the first mm or 1/ 20th inch from a centre drill, or spot drill. My mistake for decades was to use a centre drill until the second diameter struck metal, but much better if you have just the starting cone touch metal as a lead for the proper drill, as I have recently learned. But please teach me more! An interesting thread!

K


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## goldstar31 (Sep 3, 2020)

Steamchick said:


> My Aunt, a lifelong nurse, loved to find a bit of wolf in a hedge or on a fence and rub it on her hands, so the skin could benefit from the lanolin.
> 
> 
> K



A wolf in sheep's clothing?  Actually,  wolf's hair is hollow as is Arctic Dog. The hair doesn't freeze at sub -zero temperatures-- or so I was informed when I went out to Arctic Norway on a Nordic Nation's Winter Survival course.  Not all model engineering.


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## goldstar31 (Sep 3, 2020)

I'd forgotten. My late wife bought a reindeer rug up in the Cairngorms. Presumably it was from the Mikkel Utsi herd. All very emotive stuff- the Clearances after Culloden- and sheep etc etc.  We had a wee Bhutt and Bhen.
Funny old World


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## Shopgeezer (Sep 4, 2020)

Lanolin from wolf hair?  I think the typo was meant to say “wool”. Although maybe the wolf was in sheep’s clothing?


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## goldstar31 (Sep 4, 2020)

Shopgeezer said:


> Lanolin from wolf hair?  I think the typo was meant to say “wool”. Although maybe the wolf was in sheep’s clothing?



Oh Deer!  See 52.  Well when we had our place in the Cairngorms, there was the legend of the Wolf of Badenoch.  Son and his pal from uni at Cambridge went up to run a nearby campsite ran the campshop with a new product---- Bambi Burgers!


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## Steamchick (Sep 4, 2020)

I HAVE FIGURED THAT IT IS THE PREDICTIVE TEXT ON THIS WEBSITE. As an "old codger", (let it try and make "fool" out of those letters!) I have been a few weeks on this site and can't get used to the fact that the machine changes words I type correctly, and though it highlights spelling/typos that it can't manage so I can make corrections - or my computer interrupts with an advert as has already happened once in this message, causing me to type when the screen is somewhere else! - it doesn't tell me when it has changed "wool" into "wolf"! - The "f" isn't anywhere near the sheep's clothing, so it wasn't my fingers that did that one.
I reckon predictive text isn't appropriate to a technical site, where people can talk honestly about nipples (for lubrication), Bastards (for files and cuts) rubber hose (for a flexible connection for transporting fluids), bores (Engineers like me who prattle on all day) - etc.
Sorry for confusion - or glad you enjoyed the laughs - whichever is appropriate.
K


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## goldstar31 (Sep 4, 2020)

Ken

        We are experiencing some parlous events and  it was welcome fun as an alternative.
I have been in lockdown mostly alome  since FEBRUARY-- and understandably, somewhat pee-ed off.

more power to your elbow

Regards

Norman


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## Cogsy (Sep 4, 2020)

Steamchick said:


> I HAVE FIGURED THAT IT IS THE PREDICTIVE TEXT ON THIS WEBSITE...[SNIP]...
> I reckon predictive text isn't appropriate to a technical site...


What computer are you using? There is no default predictive text on this forum for me (though there is a spellcheck). If you're using a PC then your browser is providing the predictive text and it's likely an add-on that you've installed yourself (even if unintentionally).


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## goldstar31 (Sep 5, 2020)

My 'goof' was because I use an Apple PC but with a Microsoft 'Word' programme.

Certainly nothing to do with the matters here

My 'serious' views on the occurrence.  I also hit appalling and singularly ignorant knowledge of English 'English'.

Somewhat rudely, I utter the useless words 'Bugger off, my English WAS better than yours'


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## BaronJ (Sep 5, 2020)

Hi Guys,

I've turned off predictive text in Firefox, the browser I use !  I do have spell checking but its a one click request, then everything that the computer decides is not correct shows up in red !  So you either change it or ignore it.  Though I do find that highlighting UK spelling for American ones annoying.


----------



## L98fiero (Sep 5, 2020)

BaronJ said:


> I've turned off predictive text in Firefox, the browser I use !  I do have spell checking but its a one click request, then everything that the computer decides is not correct shows up in red !  So you either change it or ignore it.  Though I do find that highlighting UK spelling for American ones annoying.


Firefox has half a dozen different English dictionaries, if it isn't there, download one for the UK.


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## ShopShoe (Sep 5, 2020)

More on the spell-check. Ignore if you want.

In one of the early versions of Word, my wife's name "Debbie" kept being changed to "debauchery."

--ShopShoe


----------



## Steamchick (Sep 5, 2020)

Thanks for the tips. I'll try and figure out where the predictive text is coming from... (I have the same problem with my 10 year old phone!).
So when I spout "rubbish", I am always appreciative of the feedback - some quite amusing. But I apologise for sending the rubbish in case it is misleading. (If you find a wolf in the fence that's a "little red riding-hood" moment!).
K


----------



## Steamchick (Sep 5, 2020)

Ok... I cried "Wolf" - But I am of the Chicken family, and we are paranoid about anything with such big nasty teeth, that eats meat.
But back to drilling: What are the time honoured and approved methods of accurately locating and drilling holes?

At school I was taught - scribe lines, centre-pop, hit the centre pop by eye with the centre drill and drill until the second cone is formed, Then use the final drill.
Then I was taught (in a machine shop) to draw circles using the centre-pop as the centre for the compass, and after starting drilling the first hole close to the first circle, adjust the drilling position by centre popping on the side of least cut to move the drilling across to centre it in the next circle. Maybe with further adjustments as the taper of the drill makes the circles bigger until is starts to cut at size. (after which you can't move the hole!).
But an aeronautical mechanic advised - "don't centre-pop, as it isn't that accurate. Use a miller-driller with an accurate location cross slide table, to get the correct spacing of holes and position from the datum. Centre drill, then final drill without moving ANY slides between the drills. (All common sense?).
But then I read that the centre drill should only be taken to the first taper, as a location for the main drill, not as deep as the first parallel part.. Thus the taper of the final drill will locate correctly.
More recently, I heard that one should drill with the centre drill until the parallel part has a little depth, then the final drill will centre on its own taper, not screw around on the "blunt" tip in a small tapered hole.
Seems logical to me? - but what do the professionals do? e.g. people who make machine tools and gauges? aeroplanes? Rockets? Watches? or other high precision manufacturing?
The only precision drilling I have been doing is drilling 0.25mm holes in gas jets. - Any watch-makers with advice?
Thanks,
K


----------



## BaronJ (Sep 6, 2020)

Hi Steamchick, Guys,

Apart from using an optical center punch, I use a triangular center punch, the tip is ground like an inverted pyramid.  This provides a sharp point that easily locates in a scribed junction or line.  A spotting drill will then make a dimple that the drill point fits into.

A lot of things have altered for me since I built John Morans four facet drill grinder.  I get accurately sized holes that don't wander off.

Though I do note though that one of the reasons that holes drift off as they get deeper is drill pressure.  Basically since a blunt or poorly cutting drill needs more pressure to cut, the drill flexes and bends ever so slightly, larger drills less so, but the bending causes the drill to run off to one side or other resulting in a hole coming out in the wrong place.  This of course gets worse the deeper the hole.

I now regrind all my drills four facet, even new ones.  Unfortunately small drills, less than 3 mm are much more difficult to grind, simply because of the amount of stick out.  This is where a TCG wins out.


----------



## Steamchick (Sep 6, 2020)

Great information! I haven't heard all that before. I'm without a precision drill grinder, but do have a cheap jig/holder on the side of my bench grinder. I then finish dressing and levelling the drill bit with a Black & Decker plastic hand holder I bought in the 1970s.... which I use on a flat sheet of Carborundum, or emery. This gives drills that hardly wander - well no more than part used newish drills. But as "the job" is usually worth more than a few drills, I like new drill bits for the best jobs. 
I have modified my auto-punch by using a reground broken drill stub as the punch metal - High-speed drill steel is much better for a fine point than the original bit of case-hardened steel. I will try grinding it to a triangular pyramid now for better accuracy!
But your 4-facet grinding info sounds to be one step better for drill bits!
Thanks.
K


----------



## Steamchick (Sep 6, 2020)

Ian, Any chance of a copy of your drill grinder tool plans - mentioned a while back and I can't seem to find a link?
I've been searching the web and got confused with all the different styles of drill grinding fixtures, so haven't found what I was looking for there - yet. Maybe there is a website/link someone knows?
Ta,
K


----------



## goldstar31 (Sep 6, 2020)

I


Steamchick said:


> But your 4-facet grinding info sounds to be one step better for drill bits!
> Thanks.
> K



Really, there is  little difference between  regrinding end mills and ordinary drills,  I am surprised that no one has commented Again there is discussion elsewhere that the good old Quorn can do MOST things in refurbishing worn tools. In fact Chaddock actually made his 1/10th diameter end mills on his-- but had  job re-sharpening them. As others have said 'Read the Manual' It was 1973 when the first Quorn emerged and there seems to be little to compete. The only thing that  spoils is, is setting up time.

So I'm reducing my many bits and making a Worden as displacement therapy but once finished( when???)
it will not only do lathe tools, 4 facet drills, end mills------- and sharpen the tips on slitting saws.
All sort of in one envelope.

Meantime, I am wondering what all the fuss about drilling holes is all about.  My father used a 'Bob and Aunty' jig to make 'tubs; which were small wheeled wagons to bring coal from the coal face to the surface for sorting and thence to larger wagons to the shipping staithes- pulled by wire ropes--- which my father 'socketed' He was on 'piece work' and then in the colliery holidays, re-bed the steam locomotives- with out welding them. These old guys were 'the tops' and would give little to these 'newbies' who spent time talking endlessly.  He drew what he wanted on the dirt floor with a stick and he and his striker at the anvil simply got on with the task together.

Then in. my world, there was the smoothes and levelled rivets on unarmed photo recognisant Spitfires to get that few MPH out of trouble.

And, in case you doubt me, 'ours' is still flying in Canada . Thev old fitter from those days has jut died at almost 90. Hec was a boy of 18/19 then. So was I and at Hendon

I'm afraid but that is history and the old war bird is SL-721 and was the private aircraft of Sir James M Robb-- boss of RAF Fighter Command.


----------



## goldstar31 (Sep 6, 2020)

Steamchick said:


> Ian, Any chance of a copy of your drill grinder tool plans - mentioned a while back and I can't seem to find a link?
> I've been searching the web and got confused with all the different styles of drill grinding fixtures, so haven't found what I was looking for there - yet. Maybe there is a website/link someone knows?
> Ta,
> K



see GadgetBuilder.com and work from there


----------



## BaronJ (Sep 6, 2020)

Steamchick said:


> Ian, Any chance of a copy of your drill grinder tool plans - mentioned a while back and I can't seem to find a link?
> I've been searching the web and got confused with all the different styles of drill grinding fixtures, so haven't found what I was looking for there - yet. Maybe there is a website/link someone knows?
> Ta,
> K


Here you are !
John Moran of gadget builder will Email you his notes and plans if you ask him.

You can see my build near the bottom of the page.



			GadgetBuilder's MiniLathe and Little Workshop
		


look down the left side for the article.


----------



## goldstar31 (Sep 6, 2020)

I've just worked through a largev quanity of alcoholo as thee guest of good friend for dinner. He's a wonderful both Chinese and European cook. Well, before all this, I had just discovered that I CAN use a 25mm diameter ER32 tool holder on my original Mark One Quorn -- because, I had made split collars which would hold the suggested Mark3 set up.  my pet parrot says-- 'Who is a clever boy then'
So my ancient Mark One can move into the ethereal realms of the rather expensive Mark 3-phew!

Meanwhile-- back on the ranch- I've  got a Worden which is going to be a lot simpler and less expensive but will not only do lathe tools but drills, end mills and sharpen slitting saws. In other words, ignoring everyone else. 

So that's me- others may be different

Cheers

Norman


----------



## awake (Sep 6, 2020)

Steamchick said:


> Ok... I cried "Wolf" - But I am of the Chicken family, and we are paranoid about anything with such big nasty teeth, that eats meat.
> But back to drilling: What are the time honoured and approved methods of accurately locating and drilling holes?
> 
> At school I was taught - scribe lines, centre-pop, hit the centre pop by eye with the centre drill and drill until the second cone is formed, Then use the final drill.
> ...



Let me preface everything below with, "as I understand it" - I've only been doing this for about 15 years, and make no claim to being an expert!

With that disclaimer in place, it's all about the degree of accuracy required. If you are drilling clearance holes that are .030" larger than the bolt or screw going through, you theoretically only have to be within +/- .015" or so of the exact placement - easily doable with careful use of scribe and punch. If you need greater accuracy, then you will do better to locate and spot drill on a good mill - but keep in mind that 1) it would not be at all unusual to have a .001" or more of error in the average hobby-shop manual mill, and 2) drilling is never a high precision operation. That's why they make reamers (to help get closer to on-size and round, but doesn't help with placement). If the hole is large enough to allow it and with proper technique, boring will generally give the most accurate results as far as placement and roundness, but then the issue will be the accuracy of setting the boring head to get on-size.

In a commercial shop, spending twice the time to be more accurate than is actually needed is a poor use of time. In a hobby shop, the calculation may be different - the measure being what we enjoy spending time on, rather tfhan on $ / hr.


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## Steamchick (Sep 7, 2020)

Fair comment - but when parts need to be dowelled for alignment, drilling positional accuracy comes to the fore. I usually cheat and either use a spigot for alignment (As with cylinder heads in a bore) or assemble and align - then drill through mating parts for the dowel pins or fitted bolts.
Thanks for comment.
K


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## BaronJ (Sep 7, 2020)

Hi Guys,

This jig had the 3 mm dowel pin holes drilled and then tapped M6 holes drilled based on the mill dial readings.  The clearance holes for the cap screws were drilled 6.1 mm, whilst the dowel pin holes were spotted through.  I did cheat and bored the 19 mm hole on the lathe based on a 12 mm through hole.

If you look carefully the large hole is very slightly off to one side, simply because the pop mark should have been opened out with a small drill first.










This is a die used for punching 5 thou Teflon sheet for bearing preload washers used in a grinding spindle that I'm currently making for a TCG.  These are punched to suit the inside hole.  They will be placed on a mandrel and turned down to 21 mm diameter.


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## awake (Sep 7, 2020)

Steamchick said:


> Fair comment - but when parts need to be dowelled for alignment, drilling positional accuracy comes to the fore. I usually cheat and either use a spigot for alignment (As with cylinder heads in a bore) or assemble and align - then drill through mating parts for the dowel pins or fitted bolts.
> Thanks for comment.
> K



Yes, exactly - that is a perfect example of when positional accuracy is paramount.

Though I have to say that in my limited experience, if I want to get absolute alignment of dowels, I assemble first (clamp, bolt, spot weld - whatever is appropriate), then drill and ream through at the same time. If the dowels are to be a press fit in one side and a slip fit in the other, the above is obviously done at the press fit size; then the parts are separated and the piece into which the dowels should slip are reamed for a slip fit.

In the above scenario, absolute positional accuracy may not be essential, since the two parts have very high relative positional accuracy.


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## fcheslop (Sep 7, 2020)

The way I was shown at Smiths was to use an eye glass and a spade drill bit in an Archimedes drill to spot the hole
The hole would be near sized after drilling with a cutting broach and finished with the polishing broach on brass to harden the hole
We had to make the drill bit first.
Now I use the mill and work from coordinates and spot with a spotting drill
see attached for some basic clock work
Lesson 1


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## L98fiero (Sep 8, 2020)

awake said:


> Though I have to say that in my limited experience, if I want to get absolute alignment of dowels, I assemble first (clamp, bolt, spot weld - whatever is appropriate), then drill and ream through at the same time. If the dowels are to be a press fit in one side and a slip fit in the other, the above is obviously done at the press fit size; then the parts are separated and the piece into which the dowels should slip are reamed for a slip fit.


And if you _still_ get the position wrong you can call it foolproofing so the parts go together correctly


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## holmes_ca (Sep 12, 2020)

When we made fixtures that needed a slip fit on the top plate we ground 3 120 flats on the top portion of the dowels leaving a thin portion on the dowels OD for contact in the hole

Edmund........Alberta


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## holmes_ca (Sep 13, 2020)

And if you use tapered dowels for location if the alignment is not exact you can always re-align and use the taper reamer to re-align, can't do that with a parallel (straight) dowel?


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## SmithDoor (Sep 13, 2020)

I have Word 2000 
There is spot you can add new words 

Dave



ShopShoe said:


> More on the spell-check. Ignore if you want.
> 
> In one of the early versions of Word, my wife's name "Debbie" kept being changed to "debauchery."
> 
> --ShopShoe


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