ON topic- parting off advice

Apr 10, 2008 10 Replies

Anyone have a speed & feed solution to parting off without the thin ring left over. Doing a thin .08 washer, SS416. The ID is .315, and the parting insert is .125 wide. Straight/neutral cut.



I am getting a thin .003-.005 ring, that needs to be broken off, and the washer ID hand chamfered. I am getting really nice surface finish from the parting tool, so I would prefer to know a parting method that doesn't require a custom ground tool. I figure this problem has been solved long ago..



ca


you need one with 8-15 degree angle.

You could grind what you have, but 8-15 angle inserts are not custom.

Clay, You need to have a part off insert that has angle on it. I've had good luck with these for smaller stuff:

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I would think that you could get inserts with a similar angle on them for the blade that you are currently using. The reason I mentioned the above was for a washer your throwing away more material than your selling. That may not be an issue.

Best, Steve

An angle with a dead sharp point. I'd lean towards the 15 degree angle. On my Swiss, I use a 20 degree angle, with 18 degrees clearance (under). In fact, I also use C/O tools with the same geometry on my 5c gang lathe when I need to cut parts off clean.

Matt

Yep, I use a Iscar 15 degree 0 radius, but if I profile a chamfer I will hone a .002-.003 radius on it. I have re-ground some of them to

20-23 degrees like Mat.

If you are adverse to changing the part-off tool, chamfer the I.D. before parting off.

Great advice. thanks everyone, problem solved.

ca

You're cutting off an .08" part with a .125 tool? That seems ... somehow wrong to me.

Iscar and Kenametal have some nice .060 wide c/off tools.

So does Valenite........

Tom, I use an Iscar .087 for up to 1 1/4" stock. I have plenty of their .122 C/off inserts but use the .087 most of the time.

tom,

Seemed wrong to me too....

Cutoff length is too long for my favorite narrow cutoff holder. I have .08 also, but wrong inserts....crappy backside finish with those inserts.

run is only 40 pieces so not worth the bother to optimize....

I would however like opinions/tricks for getting nice finishes on 416.

ca

Tom Accuosti wrote:

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