A part I am running requires drilling (3) .078 dia holes 1.8 deep.
Mat'l is cast 420f s.s.
Live tool through coolant is not an option.
I am currently using a G83 peck cycle with full retract to clear chips.
per peck length = .078 RPM=3000 Feed= 4.3 IPM.
Drill is cobalt TIALN coated parabolic...
Does anyone out there have any experience with 420F?
What are its advantages over 300 series stainless?
I understand that there aren't many mills state-side that will produce it
