Who makes the best small drill bits?

[Jennifer Edwards]

Hello Everyone,

Lately I have been plagued by poor quality smaller drill bits. They either crumble, instantly dull, or break at the worst times.

Who makes the finest quality smaller, say one to three millimetre, HSS drill bits in the U.K.?

Thanks’
Jenny

 

[Dr Jo]

It depends....

"Made in the UK" - I don't think even Dormer are made in the UK any more.

"Finest" - what are you looking to drill? Carbide is better for some materials. HSS for others, four facet if you can get them.

How much do you want to spend?

Jo

 

[Jennifer Edwards]

I’m so sick of junk bits that money is not important. I’m looking for high quality.

 

[Dr Jo]

Dormer drill are easy enough to find. I also have some nice German HSS drill bits.

3.0 is a standard PCD drill size and you will find the carbide ones are useful

Jo

 

[Jasonb]

Dormer A012 split points are what I mostly use, for common sizes I prefer the Ao22 stub length ones. MSC UK usually have them at about 60% less then list look at the minthly sales flyer bottom left https://www.mscdirect.co.uk/cgi/insrhm.

Guhring are not too bad either.

How is your S&P going?

 

[el gringo]

What do you folks in the UK do about numbered drills? I use Hanson that I bought years ago when they were 'Hansen'.

 

[Herbiev]

I use Sutton tools. Great drill bits.

 

[rlukens]

I can't comment on drill quality, I buy whatever. I can say that most of the smaller drills are poorly sharpened... no relief. A light touch on my bench grinder makes a world of difference.

 

[Jennifer Edwards]

Thank you everyone for the great information, please keep it comming, as I value the opinions of other model engineers.

What I am finding is that the type available locally are made from poor materials and/or have poor geometry. This is especially true for smaller sizes.

I do not have any issues with larger sizes say 4mm and up, as I can easily reshape them. Rather it is those smaller odd sizes that one uses for tapping that I am having difficulty with. Twice in the last few months I have had to trash a complicated bit of machining due to broken bits. Today I came close to loosing two days worth of work, i was just lucky that i was able to extract it. I just hate wasting so many hours of effort due to a poorly engineered bit of tooling..

BTW - I picked up a half dozen nice large second hand heavy non-ferrous laps, from of all places, a gem and mineral show. they are impregnated with various grits of diamond ranging from 600 to 12,000 grit that are ecxellent for putting new edges on carbide or HSS tooling. They are almost impossible to damage as long as you keep them wet.

Thanks again,
Jenny

 

[petertha]

In the typical numbered sets I've had good luck with reputable HSS grinders like Precision Twist USA. In aluminum, particularly deeper than recommended depth : diameter ratio, I have found the 'specialty' drills like Walter parabolic flute do a better job vacating chips. For teeny stuff I have had good luck with these Asian carbide drills, some people call them circuitboard drills but not sure that's all they do. Just watch out for factory rejects or re-sharpened, some sellers like to play tricky games.

Some typical issues with the teeny drills are

1) not holding them concentrically as a function of the chuck or collet runout. If chuck TIR is say 0.002", that represents 6.4% on a 1/32" drill. That's getting up there. I was breaking carbide center drills in my lathe until I finally realized my tailstock was contributing to this problem. You might have to look at a good quality chuck if this is an issue. Also some chuck may have varying TIR depending on what diameter they are gripping. Good chucks typically don't but cost $$

2) when you work out the rpms on small diameter drills on SFPM & material etc. they get very high. That explains the turbine sound at the dentist office which can be in tens or hundred K rpms. So our mills & drills max out long before this. I don't have a good answer on this one. Some folks have other techniques like pecking & get the job done. I always had this idea of chucking a homebrew high speed motor + collet assembly in the mill (and just leave the rotation off). There are plenty of inexpensive, high quality, high KV brushless motors in the RC world with that would spin at 50K rpm from DC power source & easily handle the thrust duty. The trick is marrying the collet to the shaft accuratley. There are some nice CNC spindle motors with integral ER collets out of Asia but the motor cans get big, so you would have to hang it off to the side of the quill with a bracket arm which I have seen done.
https://en.wikipedia.org/wiki/Dental_drill

3) and of course everyone has their own cutting fluid recommendations so I wont get into that other than to say something should be used & is beneficial.
#1 & #2 trump #3 in my opinion.

 

[petertha]

oops forgot the 'circuit board' drills

 

[petertha]

BTW - I picked up a half dozen nice large second hand heavy non-ferrous laps, from of all places, a gem and mineral show. they are impregnated with various grits of diamond ranging from 600 to 12,000 grit that are ecxellent for putting new edges on carbide or HSS tooling. They are almost impossible to damage as long as you keep them wet.
Jenny

Can you show a pic? Do you mean a rectangular abrasive stick, or round as in lapping a hole?

 

[Cogsy]

As an aside, are you aware of the Alum trick with non-ferrous parts? It can take a long time, especially for a small diameter hole, but eventually the broken bit or tap can be dissolved away. If you have a complex part you just don't want to scrap it can be a life saver.

 

[petertha]

As an aside, are you aware of the Alum trick with non-ferrous parts? It can take a long time, especially for a small diameter hole, but eventually the broken bit or tap can be dissolved away.

Maybe... maybe not.

https://www.homemodelenginemachinist.com/threads/broken-tap-in-aluminum-cranckase.26470/

 

[Jasonb]

What do you folks in the UK do about numbered drills? I use Hanson that I bought years ago when they were 'Hansen'.

That's easy, I never use them having metric bits in 0.1mm increments from o.3mm to 10mm there is no real need for them or letter drills.

 

[XD351]

Same here , i think many get too mixed up and forget that we are making models - not working for NASA ! I have letter and number drill sets that i rarely use , i just don't get to wound up for a few thousands for 90% of the threads i need to tap its just not worth it . 60% thread engagement is good enough for most of what we do with the exception of things like head and big end bolts where i look for 75% engagement .

 

[skyline1]

Yes these Chinese carbide minidrills are really quite good I have many of them and use them for all sorts of stuff not just their suggested purpose of PCB production

It has been mentioned that they need high RPM, I run mine at 12000 in a little Chinese gantry router and even this is a bit slow for the smaller ones.

They will also work well in a Dremel type drill with a stand but are too brittle to be used freehand probably.

The miniature milling cutters are good too available in many sizes and profiles for very little cost and special ones for particular materials (aluminium etc)

I think attaching a small high speed motor head to the mill is a great idea you get the best of both worlds the rigidity of the mill and high speed.

 

[Chiptosser]

You should have good resources there in the UK to Guhring drills, they are very good quality.

You should have access to a number of good quality brands.

Find a machine shop, give them a call and ask them what is available in your area.

Remember, those small drills get spun up a lot faster then 3mm and up.

 

[olympic]

Yes these Chinese carbide minidrills are really quite good I have many of them and use them for all sorts of stuff not just their suggested purpose of PCB production

It has been mentioned that they need high RPM, I run mine at 12000 in a little Chinese gantry router and even this is a bit slow for the smaller ones.

I use a Cameron precision drill press that I found at a yard sale. Maximum RPM IS 30,000.

 

[Nick Hulme]

I buy from a commercial tooling supplier who supplies machine shops, they don't carry anything but good quality.