Regular jobber (High speed steel) bits work just fine. The technique is everything in drilling stainless. Slow speed, plenty of tapping fluid (I actually use Royal Purple assembly lube since I have it and it has a nice spout) and firm pressure are how to drill SS. If you let the drill run flat out, you will ruin the bit and work harden the SS so it eats every new bit you throw at it.

 

Bruce hit the nail, slow and plenty fluid.

I like to add one thing, Step drill. Especially with sheet metal, the drill catches both flutes before the hole is round and pulls the bit through.
With a step drill you can avoid that and these are actually designed to enlarge holes the easy way.
Good and inexpensive tool to have...

Titanium Nitride Coated Steel Step Drill Bit Set

 

BTW: they work great on fiberglass too!!:wave:

 

What Nuke said above, slowest drill speed you can do. Plenty of oil. I like the step bits but they can be a little messy on the hole sometimes. I just drilled some sailboat gudgeons with cheapo bits on a drill press, moderate pressure and slow bit speed and make sure the bit is sharp. If it work hardens you will tell it, but keep the oil on her and pressure and it will start to cut, when it starts to cut keep it going.

 

I'm with Pete; once you have a pilot step drills sail through stainless like butter.

Jeff

 

Made the drill speed error with the shifter. Work hardened & killed two drills. Dropped back & punted with smaller diameter bolts & called it a day.

I have a set (4) of stainless steel quick jacks that I want to install. The holes are a shade too small for the FL rubber grommet units. The FFR ones on now that I sprayed with black truck bed liner don't really go with the rest of the car.

Will the step drill work on something that thick?

 

Will the step drill work on something that thick?

Yes Kevin, up to 1/4inch...

 

I drill stainless at work quite often and even though the jobber bits will go through it, I find it works better to have a couple 1/8" Cobalt bits around to start the hole. I've been able to punch through tough stainless with the Cobalt bits even after work hardening the spot with the jobber bits.
Slow speed and lots of pressure is the secret as stated above. Good step drills will go through fairly heavy material in mild steel, but I'm not sure I would use one on Stainless that was much thicker than 1/8" or so. Once you have a good pilot hole, most decent jobber drills will work fine if used in a drill press.

Bob

 

I would only use a cobalt bit...any other bit will not last very long...u can try a titanium coated bit but once the coating is gone...it's just an HSS (high speed steel bit) and not worth a damn..they cost a bit more (no pun intended)but worth it in the end..keep in mind the extra work your drill will also be subjected to with cheap bits...not worth it in the end

 

slowest drill speed SLOW

I bought a new drill press so I could slow down the speed. I have paid for it with the savings on drill bits.

use tap easy or some type of lube

I have used water when I cut stainless sheets with a jig saw. Old squirt bottle that windshield clearner came in.

Oh yes, I use water when I cut plexiglass with a jig saw. Work great!

 

The step bits you can get at Harbor Freight are very good and won't break the bank. I like them more than the expensive ones I bought at home depot.

Steel Step Drill Set - 3 Piece, Titanium Nitride Step Drill Bits

Depending on the thickness of the metal and the spacing between steps in the bit, you might have to go halfway through the piece, then flip it over. But the step bits are great to have on hand. Once you use one, you'll wonder how you built the car without them.

 

Thanks All. Got the step drill & it was a quick job.

 

I thought this was pretty interesting - drilling square holes in metal.

https://www.youtube.com/watch?v=qI8QWhRUDl0