Rick Finsta
Stainless
- Joined
- Sep 27, 2017
I have always found 4140 annealed and pre-hard to LOVE SFM to get a good finish, both in turning and milling applications. I'm cutting material that has been hardened to 41-44HRc and not sure where to start. I'm using a Seco Turbo mill and their speeds and feeds seem crazy slow (I usually double them for 4140PH and that is my inclination here).
I also am not sure how to balance stepover and DOC on hard-ish material like this. I need to remove 0.106" and usually I will go as deep as 0.193" in material like this in a higher HP machine, but with around 10HP I am staying under 0.100". I also get a lot of smearing if I run a thin finish pass (say, 0.015" or so) in the 28-32HRc stuff so I was thinking of just splitting this into two even or near-even DOC passes with around a 6% stepover on a 2" face mill.
Thoughts? I've gotta get these knocked out and over to EDM for some holes. I don't wanna blow $300 on inserts testing things out. LOL
I also am not sure how to balance stepover and DOC on hard-ish material like this. I need to remove 0.106" and usually I will go as deep as 0.193" in material like this in a higher HP machine, but with around 10HP I am staying under 0.100". I also get a lot of smearing if I run a thin finish pass (say, 0.015" or so) in the 28-32HRc stuff so I was thinking of just splitting this into two even or near-even DOC passes with around a 6% stepover on a 2" face mill.
Thoughts? I've gotta get these knocked out and over to EDM for some holes. I don't wanna blow $300 on inserts testing things out. LOL