Turning "hard" pure copper -- sharp Al-style or blunt steel-style inserts?

[Finegrain]

Hi guys,

I need to turn some pure copper tube. It is described as "tempered hard". No fancy turning, just trimming part of the 7/8" OD to .855", chamfering the ends, and cutting off.

I have very sharp Korloy uncoated inserts, and standard TiAlN coated steel/stainless steel inserts.

Which would you choose?

Thanks, and regards.

Mike

 

[alphonso]

You should use very sharp, very high positive (10- 20 degree) tool. HSS works well.

 

[BugRobotics]

Yep, the sharp stuff. I use aluminum specific inserts to cut dead soft and "hard" varieties of copper regularly. I usually have one insert in a holder that is used and one that I keep fresh for my final cuts. Makes a difference with surface finish and tool pressure.