My lead told me to bump up the feed rate on that tricky 4140 job

I was worried about chatter, but he was right, it actually ran smoother and cut my cycle time by almost 15 minutes. Anyone else have a 'go against your gut' tip that worked out?

3 comments

3 Comments

cameronschmidt1mo ago

What specific feed rate did you end up running at? I mean, 4140 can be so touchy, I'm surprised it worked.

iris_davis901mo ago

My feed rate was basically a prayer and a guess.

taylor6681mo ago

Yeah the part about "my feed rate was basically a prayer and a guess" from @iris_davis90 really hits home. But I gotta ask, what tooling were you running? Because with 4140, the difference between a coated carbide and a good ceramic insert is night and day. I've seen guys try to bump feed on 4140 with a standard carbide and it just blows up. But with a good grade insert that can take the heat, the higher feed actually helps keep the heat in the chip instead of the part. Were you using a specific chipbreaker geometry or just a general purpose one?