[cdlenterprises]

My company cuts alot of 15-5PH in the H975 condition. Lately we have been toying with the idea of switching to Project 70 15-5PH which is supposedly a free machining version of the alloy. The question is how much easier is it to machine than the regular stuff? Has anyone had experience with Project 70 alloys? Any recommendations for milling speeds and feeds?

[cdlenterprises]

No one cuts this stuff?

[Cruiser]

I used to turn impellers in a large vertical lathe that were 15-5Ph castings. The rule is the same as what you have been doing. Slow or ceramic and no dull tools. We started roughing with ceramics, and it was a glow in the dark job ! Its the finishing tools we had to worry over, if they dulled and glowed then retract and try to re-cut the rub area, well, sometimes it took some doing to get back to where ya need to be. The problem we encountered most was that of the programmers point of view, he insisted on cutting the whole of the form in one continuous pass without regard to tool life, so it was the operators job to pick a good point to retract tool etc. !