In this video we are machining up inserts to go inside 380kg plates to that eventually will make up the body of our 3.0m Megadrill. As you can see from the extended facing passes in the video... it's time to retire our 20yr old bandsaw. It cuts as straight as a question mark.

We are using mostly New Iscar WNMG tips
2.53.5mm depth of cut.
VC170

Feed rates:
Facing 0.3 Rough, 0.25 Finish
Turning0.33 Rough, 0.25 Finish

Internal Grooving Tool
VC100
Feed Rate 0.16

As I mention in the video, if any machinist have made an Iscar grooving bar chip on 4140 doing internal grooves, by all means SHARE it in the comments.

Thanks for tuning in!