drilling 17- 4 stainless steel

[vince05]

Recomended feeds and speeeds for drilling 17-4 stainless steel using HSS .250 dia 90 degree SPOT DRILL AND .089 dia 135 degree drill. please help

 

[btrueblood]

What temper is the stainless part? If fully hardened, HSS will have a tough time, you may want to get carbide drills.

 

[vince05]

17-4 stainless steel is annealed.

 

[saberblue]

Get the data from your drill supplier -- remember that the 17-4 work hardens easily so you will [probably want to use a very aggressive feed rate and moderated RPM so that you don't have to repeatedly cut through the work hardened layer -- you will also probably want to use a fluid with high levels of both hydrodynamic lubrication (straight cutting oil or HD soluble oil at high concentration) and EP lubrication ideally both chlorine and sulfur

A.R. "Andy" Nelson
Engineering Consultant
anelson@arnengineering.com

 

[unclesyd]

We drill thousands of holes in PH steels using Guhring Drills.
Here is some information in a packet of drill bits used on 17/4 in the H1125 condition.
Art. No 658 K
DIN 338 RN
S-Bohrer GT1
3.20 mm
HSCO ED BB
These are Ti coated drill bits that can stand several resharpening.