Carbide Tip Sises

Hi,

I'm very sorry to take up people's time with what must seem like a very daft question.

I've always worked with HSS in the past but I'd like to try carbide tiped lathe tools. How do I work out which carbide tips will fit which tools? Are the carbide tips standardised so that tips from one manuafacturer will fit tools from another manufacturer or do tips from different manufacturers all have different dimensions?

None of the tips for sale seem to state dimensions so I'm finding it very difficult to work out which tips will fit a tool a friend gave me.

Many thanks,

Will

Will

It's not a daft question! However, I'm afraid that your hope for standardisation amongst manufacturers is doomed to disappointment! Having said that, there are some which are interchangeable, but unless you're very lucky....

Quite a few traders at exhibitions have carbide tips for sale; it's a case of taking along your tool to a show and trying them for size.

There are also a lot of grades of carbide to suit sifferent materials, so you may find the ones you buy are not ideal.

Accessing websites such as Sandvik may help you with dimensions.

Good luck!

I think there was an article recently in either ME or MEW that detailed the meaning of the codes for the tips, the first few items include the tip shape, clamping method and size, after that I think is material but that may be manufacturer dependant. In theory standard tips of the correct type should fit any tool holder,

From my limited experience I have found that the easy way of seeing what tip a tool uses is seeing that suppliers part number. I also think that limiting the number of tip types you have makes sense. I have a couple of tools that use CCMT9 tips these are 100 degree diamond shaped, one of the tools uses the other 2 corners to get the most out of the tips.

You can find an explanation of the coding system for sizes here: http://www.ccpa.org/pdf/B212_4.pdf

Russell.

Hi Will,

These charts explain the ANSI and ISO standards for replaceable carbide tips. Shape, size, thickness etc are all specified.

Best regards

Terry

Thank you very much for the charts - now I can begin to understand the cryptic codes describing the carbide tips.

Thank you also for mentioning Sandvik - I've always reckoned that their woodworking tools are good quality so it seems a good idea to try their metalworking tools. Thank you also for the link to the

Sandvik catalogue - I'll spend a few days reading through that.

Thanks for the advice about the radius to use for removal and finishing cuts.

Is there any supplier that's particularly good for selling Sandvik tools and tips in small quantities by post or is eBay the best place to look?

Any other advice greatfully received!

Will

Peter at Greenwood Tools is an ex Sandvik man and can help you as well.

K

Hi Will,

One thing that is often overlooked by "hobbyists" when choosing which tip to buy is the chip breaker. This is far more important than often thought. A decent manufacturer of tips will list the depth of cut (DOC)figures for each of their tip's chip breaker, there is no point in buying a tip that will only work with a 5mm DOC! We as hobbyists will often require to take cuts of a few thou or less, so picking a tip with a chip breaker capable of such a cut will pay the time taken to find the right one. Picking the wrong tip, easily done, will lead to disappointment, you have been warned.

Why is rated DOC important? Well if a manufacturer says a tip can take a small cut, they mean it will still give a good finish at that DOC. The fact that a tip that is meant to take a large cut will still remove metal is completely irrelevant if the finish it gives is like a ploughed field.

As for a good make, Sumitomo are a very reputable supplier, proving you get the right shape, grade, tip radius, and of course chip breaker, for the job in hand. Who said life was meant to be simple?

Any wonder why I am a fan of Tangential tooling?

chriStephens

... On this information, and from what I know. Always buy ISO style (shape) tools and the tips to suit. This way, if you know the ISO form, you will have the pick of the bunch (and price). You will know what you are buying and that it will fit the ISO tool you have. Buy a non ISO tool and you will always have to buy from one or fewer manufacturers, this will normally cost more than ISO style tips.

Thanks - I'll try to give Peter a call.

Thank you for the advice about the chip breaker and DOC. Is this the reason why a lot of people report having big problems getting an acceptable finish with carbide tips?

I've read that the sharpness of tips affects the surface finish - how significant is this?

Thanks for the advice re. ISO - I'll definitely stick to ISO.

Will

The tips I use are for my 50mm facecutter on the mill, origionally I used the tips that were supplied, these had a chip breaker, when that firm went bust, I went to another, and when I asked for new cutters the guy behind the counterthrew his hands up in horror, he said, no these are what you want, they are plain , flat topped cutters. Appart from being cheaper, the finish improved, and the cutters lasted much longer. When they are warn out on the mill, they get use on the lathe, or on fly cutters on the mill. The good work on the lathe is done with HSS. Ian S C

I've got a tool for carbide tips from the garage next door (who're kindly letting me use their small lathe). It looks like it takes 10mm wide triangular carbide tips (ISO Shape code A). Would anyone be willing to give me a recommendation for the best tips to buy to get a high quality finish on steel and brass with light cuts?

Based on what Graham, KWIL and Chris said, I think I've some idea what tip to buy but a recommendation from someone with more expertise would probably be much better!

First thing I'm hoping to do when I get the carbide tips is cut the same piece of steel with carbide tipped and HSS tools and see what gives the best finish. Any suggestions on how to measure the finish without an expensive digital meter would be valued!

Just had a look through a machine tool suppliers catalogue and the new milling tools (some of 'em with 11 carbide tips on one tool) make me standing at the gridnding wheel with my chunk of HSS look like something out of the Flintstones! - Maybe the old technology is best though - only one way to find out...

Will

See here for the results of some trials using carbide inserts:

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

If you're only going to be taking light cuts I wouldn't bother with carbide inserts, you won't get any of the benefits of them. I've never met Graham or Chris, but I have met KWIL a couple of times, and I can tell you, he is an expert on using carbide inserts.

Picking up on another point from an earlier post I seem to do things backwards, in that I use a 0.8mm radius insert for roughing and 0.2mm for finishing. I think there's a rule when using inserts that the depth of cut should be greater than the tip radius. I'll have to look into this, I also feel an experiment coming on!

Regards,

Andrew

I thought that I would elaborate on my comments on chip breakers so, for those interested take a look at, http://www.sumicarbide.com/inserts_chipbreakers.htm .

http://www2.coromant.sandvik.com/coromant/pdf/Turning/eng/C1020_15_screen.pdf might also prove of interest.

chriStephens

Chris: Thanks for the links; very informative, you've saved me the time I would have spent searching for the information. The Sandvik link in particular seems to confirm my intuitive understanding of the cutting process, both in terms of tip radius and radial cutting forces. I assume that in order to turn a part to size it's a good idea to minimise radial cutting forces.

Regards,

Andrew

Thank you very much for such carefully thougth out work and for sharing it with us.

Thanks also for the link to the Sandvik and Sumi info.

>I think there's a rule when using inserts that the depth of cut should be greater than the tip radius. I'll have to look into this, I also feel an experiment coming on!

Let us know the results!

Will