# Soba carbide tooling



## skyline1 (Sep 28, 2012)

Hi All

Does anyone have any experience of Soba carbide lathe tooling sold by Chronos in the U.K.

They are a budget brand and I am considering buying some as I expect to be machining some pretty tough materials shortly.

My next project is going to be a Minijet (Wren MW54 hopefully) which will involve machining EN24T, Stainless and possibly even Inconel so I doubt HSS will be up to it. 

I have been after some indexable carbides for some time anyway.

Regards Mark


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## Jasonb (Sep 28, 2012)

They only do a few sets of cutters from Soba who mostly make tooling, problem with teh sets is they often have several tools that you won't use.

Look at the site that Chronos have now set up for the Glanze cutting tools, I've got several and they are fine, anyway its the quality and type of tip that will make the most difference not the holder.

J


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## skyline1 (Sep 28, 2012)

Hi Jason

I've been thinking about the Glanze ones but as you rightly say it's the tips themselves that are important and if these soba ones take standard size tips I can use whatever tips I feel comfortable with If I can cross reference them with other manufacturers. 

The Set I'm considering is CG214 3/8" shank which take CG218 Triangular tips.

I have been a traditional "grind your own" merchant up until now but high duty steels are a whole different game and I haven't got much experience with throwaway carbides apart from very occasionally in industry. Then you just go to the stores and say "have you any tips for this please" 

So if anybody has used these a cross reference list  would be very useful.

Regards Mark


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## Jasonb (Sep 28, 2012)

skyline1 said:


> The Set I'm considering is CG214 3/8" shank which take CG218 Triangular tips.


 
You really need to find out the exact spec for the tips before you buy a set as CG218 is not a standard ref number its just Chronos code. Not much use if the range of tips is limited.

I suspect they are TCMT style tips but would need to know the size to get the next bit of the ref.

J


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## titex (Sep 28, 2012)

Mark,
              If you are planning machining ANY of the inconels [or any of the HRSA's] you will need to have very rigid machines. Inconel is not especially hard, but it is very, very tough.
       Hss  in grade M42 is still used for turning any of the HSRA's  when the cut is heavily interrupted. Really without knowing what type of lathe / milling machine you have,
  unless it's an industrial production type, Inconel will NOT be good to deal with. It really requires very heavy feed rates.  The EN24T will be a whole lot easier in comparison.
                                                                                                      Regards,
                                                                                                       Titex.


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## skyline1 (Sep 29, 2012)

Hi Titex

Thanks for the Info It's a Myford ML7 which whilst not being in the production category is considered a toolroom lathe and is pretty rigid. This is not something I would consider on a minilathe for just this reason. The lathe whilst elderly, has recently been refurbished and has the feel of an almost new one.

I am trying to find out exactly what size these tips are as special tips are availabe for just this sort of material. I will contact Chronos again and see if I can find out. But they do not seem too forthcoming with information. I suspect the very reason these tools are so cheap is that they use a non standard size.

It is good to know that I could use H.S.S. if I need to. But can M42 grade be ground with standard wheels or would I need a green grit carbide one.

Regards Mark


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## lensman57 (Sep 29, 2012)

skyline1 said:


> Hi All
> 
> Does anyone have any experience of Soba carbide lathe tooling sold by Chronos in the U.K.
> 
> ...


 
Hi Mark,

Don't bother with them, utter rubbish. I have two sets of them and they are not worth the money. I only keep mine as a last resort spare .

The glanze stuff mentioned were reasonable in price before all the recent price hikes, still at least they are usable. I use the tool shanks with either Iscar or Sandvik tips and they are ok. The Glanze stuff tkae the normal ccmt or dcmt standard tips.

M42 is an 8% cobalt hss alloy and could be cut with the normal grinding wheels, the white ones cut cooler so there is less risk of burning the tip during the grind. The one that I am interested in at the moment is Crobalt alloy tool bits but these do not seem to be available in the UK or at least I can not find them.

Regards,

A.G


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## skyline1 (Sep 29, 2012)

Hi A.G.

Thanks for the heads up on this one. I was beginning to come to the same conclusion myself. I was a little suspicious when Chronos didn't quote an ISO tip type. Your experience with them has confirmed things and saved me from an unwise purchase.

As some of the materials and castings for this job are quite expensive I can't afford too many mess ups ! I am fairly sure the lathe can cope it's as tough as old boots and pretty accurate since it's refurb but I will need some good tools.

So I am now leaning towards the Glanze tools and as a bonus I have found out I have a local supplier who deals with the likes of Sandvik and Kennemetal. I thought they had closed down but it appears they have just moved a couple of miles.

I have also had a quick look at the Sandvik website and you can get CCMT tips (among many others) for just about any material and application you can think of.

As I said I am fairly new to throwaway tip tooling and still have some to learn so your advice was much appreciated.

That Crobalt sounds pretty exotic It's a Chomium/Cobalt tool steel I presume.

Regards Mark


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## titex (Sep 29, 2012)

Mark,
           Not knowing what a Wren MW54 is [but the use of Inconel would suggest a high temperature app ] so maybe a jet /rocket engine? If it is, then now I know the type of lathe you have
my biggest concern is your ability to hold a tight tolerance [your lathe not you]  Any of the HSRA's do not respond well to small depth of cut / light feed rates. The Myford is a fine model engineering lathe, but really would be totally unsuited to the machining of Inconel.  You are correct about expensive materials Inconel is horrendously expensive and I really would not like you to have to scrap a piece of it. 
As for the Soba / Glanze toolholders forget what you hear about the tips being the most important, the whole interface is critical,
  the insert seat, the insert, and even the screw.
so if you are determined to try the Inconel then, either get a recognized make of toolholder ie Sandvik Coromant, Walter or such, or go the M42 route in which case you only need to grind the blank to the desired angles.
I don't mean to fill you with dread, but unless you have dealt with any of the HRSA's  you could be in for a nasty [and costly ] surprise.


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## ninefinger (Sep 30, 2012)

Mark,

I think you (or anyone else) would do well to read this write up on using carbide with home shop machines.  I found it well written and very helpful, but long as he forewarns.  
http://www.homemodelenginemachinist.com/f20/selecting-tungsten-carbide-turning-inserts-small-manual-lathe-long-10175/#post193300

It has helped me with choosing better inserts for my machines and if I had read it before I bought I might not have ended up with holders for inserts that are difficult or more expensive to obtain.

Mike


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## wheeltapper (Sep 30, 2012)

I know its a bit late now but as others have said, they are cr*p.

I bought a set when I first started and they are still at the back of the cupboard.
If you were closer I'd give you some.
Roy


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## lensman57 (Sep 30, 2012)

skyline1 said:


> Hi A.G.
> 
> Thanks for the heads up on this one. I was beginning to come to the same conclusion myself. I was a little suspicious when Chronos didn't quote an ISO tip type. Your experience with them has confirmed things and saved me from an unwise purchase.
> 
> ...


 
Hi mark,
Crobalt is a Chrom and Cobalt alloy but the Cobalt % is very high, up to 50%. It can cope with very high cutting temp without loosing the edge and could be cut with normal grinding wheels, the only caveat is that  it is very sensitive to thermal shock, so no quenching during grind up and no sudden injection of coolant during cutting or you risk having a mini tool explosion. The Glanze tool bits are ok and the tool geometry and the screws are lets say within working tolerance. The only problem is that during last year all the major tool suppliers in thr UK, Chronos, Arc, Axminster and Warco have increased the prices by up to 30%, Glanze stuff I believe are made in India and they are not as good a value as before but then again they are not asking  even a fraction of either the Iscar, Sandvik or Seco prices . If you need to machine hard materials, then I am afraid that carbide tooling is the only choice. BTW, people make too much about carbide needing a super rigid and powerful lathe, given a small or hobby lathe you may not be able to take 0.005 mm cuts with carbide but the tools are servicable and I have no problem using the dcmt type with either my Sherline or Taig lathes so long as the tip radius is 0.2 mm, ie: sharp. so look for something like dcmt 07 02 02 or ccmy 06 02 02 not 06 02 08.

Hope that I have not confused you.

Regards,

A.G


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## Jasonb (Oct 1, 2012)

There is an ongoing thread on ME forum about testing various tips on different hardnesses of metals.

Latest test was on silver steel ( drill rod) hardened to 60Rc and the finished cut was very good but so it should be using CBN inserts that cost £25 each!!

http://www.model-engineer.co.uk/forums/postings.asp?th=51900

J


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## skyline1 (Oct 1, 2012)

Hi All

Many thanks for all the advice on this. I now feel much more confident about my first foray into DCT tooling. Its A bit of a minefield but I have a better map of it now.

Titex, Yes It Is a miniature Gas Turbine here's a link to Wren's website if you would like a look (Complete Drawings) http://www.wrenturbines.co.uk/mw54-turbo-jet-and-turbo-prop-second-stage-plans 

Wheeltapper





> I know its a bit late now but as others have said, they are cr*p.
> 
> I bought a set when I first started and they are still at the back of the cupboard.
> If you were closer I'd give you some.


Just about sums it it up, Avoid like the plague I think.

Lensman 57


> Hi mark,
> Crobalt is a Chrom and Cobalt alloy but the Cobalt % is very high, up to  50%. It can cope with very high cutting temp without loosing the edge  and could be cut with normal grinding wheels, the only caveat is that   it is very sensitive to thermal shock, so no quenching during grind up  and no sudden injection of coolant during cutting or you risk having a  mini tool explosion. The Glanze tool bits are ok and the tool geometry  and the screws are lets say within working tolerance. The only problem  is that during last year all the major tool suppliers in thr UK,  Chronos, Arc, Axminster and Warco have increased the prices by up to  30%, Glanze stuff I believe are made in India and they are not as good a  value as before but then again they are not asking  even a fraction of  either the Iscar, Sandvik or Seco prices . If you need to machine hard  materials, then I am afraid that carbide tooling is the only choice.  BTW, people make too much about carbide needing a super rigid and  powerful lathe, given a small or hobby lathe you may not be able to take  0.005 mm cuts with carbide but the tools are servicable and I have no  problem using the dcmt type with either my Sherline or Taig lathes so  long as the tip radius is 0.2 mm, ie: sharp. so look for something like  dcmt 07 02 02 or ccmy 06 02 02 not 06 02 08.
> 
> Hope that I have not confused you.


No you have not confused me quite the opposite. I think I will get a couple of Glanze carriers and tips for some experiments on similar materials, though not on the castings themselves, I should be able to pick up some stainless oddments as we have a stockholder nearby. And possibly even a little bit of Inconel. With The NGV casting (ANC5B) at £100 and the turbine rotor (Inconel 713C) at £110. A little practice is in order I think.

I agree with you about price of Glanze tools they have gone up a bit of late But if you really want a fright have a look at the price of Myford spares. Since the Myford Name and spares business got took over, ouch !
especially on little bits they want obscene money for them.

As for tooltip radii I'm right with you on that most of my H.S.S. bits have small radii and in some cases none at all. Again a newbie question but could you explain how the numbering system works I am a little unsure.

Crobalt looks like like a possibility If I can find some (If you find a source please let me know) but If you shouldn't quench it when grinding (thermal Shock) do you let it cool naturally and just take your time, ideally don't let it get too hot in the first place (very gentle grinding) I guess.

Again many thanks for the info fellas and the links to other sources very useful indeed.

Right I'm off to see a man about a tool and some stainless "Dummy Mines"

Regards Mark


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## Jasonb (Oct 1, 2012)

Click on the virtual catalogue icon on this suppliers site then have a look at pages 393 & 393, it has a good easy to follow chart. They also sell a wide range of insetrs.

http://www.mscdirect.co.uk/cgi/insrhm

If you are ordering Glanze stuff then add a couple of their inserts for Aluminium to the order as they are very good.


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## skyline1 (Oct 1, 2012)

Hi Jason

Thanks for that link It explains it all great I'm singing from the same hymn-book as everyone else now. 

Do you think I should go for DCMT (80 Deg.) or CCMT (55 Deg.) profile on tough steels like this.

Regards Mark


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## Jasonb (Oct 1, 2012)

I would say the CCMT are sturdier, they are mostly what I use but do have a holder for the DCMT which is handy for getting into tight spots.

J


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