Drilling stainless steel question


New Member
Nov 29, 2019
What's the easiest way to drill 1/8 in holes through a stainless steel rain cap, top plate (vertical portion) & liner.
I must be doing something very wrong. I'm using a new DeWalt cobalt bit, going slow and keeping everything cool... and this is taking forever.


Staff member
Nov 18, 2005
South Puget Sound, WA
Centerpunch to start. Use a cobalt bit with a 135º point angle that has a titanium carbonitride coated tip. Put a drop of oil on the tip before each hole.

Bad LP

Minister of Fire
Nov 28, 2014
Northern Maine
Problem with stainless steel is some grades can be work hardened. Once that happens you’re screwed.
Easy pressure. Slower turning speed. Lots of cutting oil. The oil needs to be on the drill points. A drop at the start with nothing during the process is absolutely useless.