HSS lathe cutoff/parting tool question

Why don't people always use the thinnest parting tool blades made? On my little lathe I have found that I simply can not use 1/8" HSS blades but the 1/16" ones work OK. I'm getting ready to tool up my

16" lathe and I'm wondering ..

Grant Erwin Kirkland, Washington

Reply to
Grant Erwin
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I use both, and even some bigger ones, depending on the material, the rigidity of the lathe and the power it can develop.

You saw my big Clausing. I can run a 3/16 parting tool with it, no problems. I sometimes use a big parting tool as its easier for me to grind in features such as chip breakers, tit cutters and other forms, in a bigger tool. The Hardinge you saw, usually gets a 1/8" or smaller tool, as it tends to slip the belts if I try to get burly with it, making customized cutoff features more problematic.

Plus, I have been known to break 1/16" cutoff tools fairly regularly when trying to push a cut in stainless steel, even with flood coolant.

Shrug. YMMV

Gunner

"At the core of liberalism is the spoiled child - miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosphy of sniveling brats." -- P.J. O'Rourke

Reply to
Gunner

Reply to
Steve Lusardi

Rigidity counts.

The larger machine will be able to handle a wider tool without chatter or breaking simply because of its mass and solidity.

Really lathes should not be rated in their swing or length, but rather, 'how much linear length of tool can you engage in the workpiece before it all comes unglued.'

Jim

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Reply to
jim rozen

jim rozen scribed in :

hah, by the time the marketing droids get done with that it'll also be useless

swarf, steam and wind

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Reply to
DejaVU

While this is certainly true, a retired machinist friend told me the following trick: I have one of those blade sliding in a holder cutoff tools. The blade is 3/32" wide and was giving me a terrible time with chatter on my Smithy 3-in-1. My friend suggested that I grind the front of the tool less steep - i.e. smaller clearance angle. A little experimenting to get it just right and no more chatter.

Ted

Reply to
Ted Edwards

I think it is a matter of the diameter of the part being cut off. A

1/16 blade is good for things less than a 1/2 inch in diameter, but not so good for 4 inch dia stock. So if you are going to part 4 inch stock, you have a thicker tool and then just use it for all parting.

Dan

Reply to
Dan Caster

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