I used to swear by running my end mills at the book speeds until a job in Tacoma last month proved me wrong.

I was burning through tools on a simple aluminum job until an old-timer on the floor asked if I'd checked the actual chip load with a microscope, which showed my 'perfect' feeds were just rubbing the material.

2 comments

2 Comments

gavine411d ago

But come on, how many shops are really burning up that much money? Most guys I know just run the book numbers and get the part out the door.

claireg811d ago

Wasn't there a big thread on Practical Machinist about this exact thing? Some guy posted photos of his chips from a 6061 job. The book speed gave him dust, but when he bumped the feed way up, the chips actually curled and came off blue. He said the sound changed from a whine to a rip. Makes you wonder how much time and money gets wasted on "perfect" settings that are just wrong for the real setup.