Old timer told me to run my end mills slower and I argued for weeks before trying it

I was running some 4140 steel at 3500 RPM on our Okuma at the shop in Dayton and this guy who's been there since the 80s said I was burning through tools. He said drop to 2200 RPM and bump the feed up 15%. I ignored him for three weeks until I blew through $80 in end mills in one afternoon. Finally tried his way and my tool life more than doubled. Anybody else have a stubborn moment like that?

2 comments

2 Comments

irisg5714d ago

Ha! Yeah, been there. I argued with our shop foreman for a month about cutter speeds on some stainless steel parts. Told him my CNC knew better. Kept chipping inserts left and right and swore up and down it was the material. Finally one Friday afternoon he came over, changed my feeds and speeds without asking, and walked away. Next Monday I ran 40 parts on one set of inserts. I had to eat my words and admit he was right. That was ten years ago and I still hear him laughing about it every time I start a new job.

terry_barnes14d ago

Those old timers usually know their stuff.