My lead told me to run the new Okuma at 80% feed, and I should have listened

We got this new Okuma lathe at our shop in Dayton, and I was setting up a tricky 4140 steel part. My lead, Dave, said to drop the feed to 80% for the first piece, but I thought I could run it at 100% since the speeds looked fine. The insert chipped halfway through, and I had to stop and reset everything. Has anyone else had a part material just eat an insert when you pushed it a little too hard?

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3 Comments

adam6526mo ago

Oh MAN, 4140? You ran 4140 at full feed on a brand new setup? That's the part that gets me! That stuff can be so nasty if it work hardens even a little. Dave was trying to save you the headache, those first piece jitters are real.

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fionaw545mo ago

4140's more about heat treat than work hardening, actually.

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robert_craig6mo ago

Yeah, "first piece jitters" is why I always sneak up on the feed with that stuff.

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