# Holder for carbide inserts for lathe



## GaryK (Dec 22, 2012)

At some point in time I acquired about 5 boxes of TNMM 322 inserts.

I would like to get some tool holders that they will fit. I have looked through all the catalogs but I'm still confused.

Is there specific type of holder that will fit these or will they fit in more than one type?

I'm looking at a set of holders that say they fit TT style inserts and I can't find anything about TT inserts. Will my inserts fit them?

Will THESE work?

More confused than ever.

Gary


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## flutedchamber (Dec 22, 2012)

Are you sure the inserts aren't TNMN?

It would be size dependent.  Such as T (TRIANGLE) N (ZERO CLEARANCE) M (I.C. .002-.004, THICKNESS .005) N (NO HOLE OR CHIP BREAKER) then a series of two or three numbers.

To to http://www.lovejoytool.com/insnomen.htm  and print the page out.  It makes  things less confusing for you and is a great reference.


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## FarFar (Dec 22, 2012)

Hello Gary

You can make something vastly better than commercial Yourself like the picture shown
TNMM s have no clearance angles so You need to tilt the inserts 5 to 7 degree
Not to difficult

Kind regards

Can we have a picture oflathe and inserts?


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## DMS (Dec 22, 2012)

Don't think that holder is what you want. The reason is the second letter in the designation. The holder you linked is for C style, which has a 7 degree relief angle ground into the insert, and is usually presented to the work "flat". The inserts you have are "N" or "neutral" inserts. They have no relief built into the insert, and so, the relief has to be built into the holder. The neutral holders/inserts are more common anyway. 

Here is a cheat sheet on carbide nomenclature

http://carbidedepot.com/formulas-insert-d.htm

(This one is easier to follow than the lovejoy link, at least for me)

If you get a holder from Enco, you probably want one of these guys http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=7908877&PMAKA=422-2940

That one is pretty pricey, so I would shop around. A lot of people have moved from the T type inserts to the trigonal (W) type, and I have found fewer T type holders recently. In any case, I would recommend a MTJNR/L, MTGNR/L or MTANR/L. Hopefully somebody will correct me if I'm wrong 

You can also make your own toolholders. Jumps4 had a good thread going on his build of some V style turning tools.

-DMS


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## PurpLev (Dec 22, 2012)

you'd want a insert holder that can hold triangle inserts with negative relief meaning that the insert holder itself should have the relief angle build into it (And you could use the inserts on both sides which doubles the number of edges you get from each insert).


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## GaryK (Dec 22, 2012)

Thanks for all the comments. I think that I will just make my own holders. They look simple enough.

Gary


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## Syaminab (Dec 23, 2012)

Gary, most of the time, is faster and better suited for a specific jobs, but never cheaper. It takes here usually 5 weeks to get any holder, so I ended up making my own, and have gone quite complicated, like this 8 insert shell mill for 9 mm APKT carboloy in 3" diameter. Good thing is that I keep the process sheet, cnc programs and we can redo them over and over when needed.

regards


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