My mentor told me to never run a 1/4 inch endmill at less than 1,000 RPM

Tried his advice on some aluminum last month and the tool snapped after 3 parts. Should I have slowed it down more or was the material too gummy for that speed?

2 comments

2 Comments

andrew_wood721mo ago

I read a post once where a guy said running an endmill that slow in aluminum is asking for trouble because you're basically rubbing instead of cutting. The heat builds up and the material welds to the tool. 3 parts sounds about right for that combo. You probably needed more like 3,000 to 5,000 RPM and a decent chip load to clear the heat out.

gray_smith671mo ago

Damn, that sucks. I've been there myself with a 1/4 inch endmill in aluminum and it's not fun. @andrew_wood72 is spot on about the rubbing issue, aluminum gums up fast when you're not making a real cut.