What kind of drill bits for metal?

[JEDI]

So um.....still not answered, what kind of metal is it that you're trying to drill into?

aluminum and stainless steel 1/4 and 3/8 inch.

aluminum is soft. i bet an el-cheapo walmart bit would work.

stainless is what i'm worried about. (also 1/4 and 3/8")

 

[DrPizza]

:thumbsup; for cobalt bits.

And I agree about spade bits vs. auger bits. The spade bits are nice, only if you have a small number of holes to drill. Those things die quick, especially in hardwoods.

 

[bruceb]

Any good high speed metal cutting drill bit will work fine in stainless steel. Just be not to get the low quality carbon types. If you are going to make many holes, it may be better to buy the titanium or cobalt bits.

 

[Colt45]

HSS is fine... lots of loading, slow, and throw some tool oil on that stainless. It work hardens like a bitch if you drill too fast.

 

[Howard]

Yep, in stainless you want to go spin slow but have a higher feed so that you take off comparatively more material in each rotation.

Are you drilling for a bolt or rod to go through? Make sure you pick a size that gives you enough clearance because drilling with a twist drill bit can often lead to non-round holes in stainless.