Drilling stainless steel question

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Dad

New Member
Nov 29, 2019
7
PA
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.
 
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.
 
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.
 
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A drop at the start with nothing during the process is absolutely useless.
Why is that?
I've been bad about using oil and wonder about the benefits.
 
Why is that?
I've been bad about using oil and wonder about the benefits.
cutting oil cools and provides lubrication to the cutting edge. Understanding feeds and speeds helps a great deal.

I can drill something like a mad man once or I can work till coffee break with the same cutting tool treated properly. The tougher the working materials the more important it becomes.
 
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