Drilling through quarter inch thick hardened stainless.?

Question

I have went through 3 cobalt drill bits trying to drill through a quarter inch thick piece of what I assume to be stainless. The reason I think it is stainless is because i know it has been exposed for at least a year with no rust or discoloration and it is also very heavy (rules out titanium). The band of steel is ¼ thick x 1 ½ wide. Any suggestions as to speed, type of bit, lubrication, etc., will be greatly appreciated!

Answer 1

the cobalt bits are the best. drill small pilot holes and cool your bitt by spraying anti-freez on it.

Answer 2

The biggest mistake most people make when drilling in stainless is to spin the drill as fast as they can. Heat builds up and work hardens the steel, after that you are screwed. The sheet metal guys here do stainless counters for commercial kitchens all the time. They taught me to pulse the drill. Trigger the drill in one second on, one second off pulses and use plenty of oil for lube. They use bits and hole saws to cut this stuff all the time and they manage to make them last this way.

Answer 3

Start with a small bit and work yer way up. WD-40 or any kind of cutting oil will help in keeping the bit cool. Start the bit out slow until you get a bite then increase speed and apply more pressure as needed. A titanium tiped bit is also helpful.

Answer 4

I just popped in because I've lost dozens of proper bits attempting this in door kick plates. Certainly a pilot hole, a lubricated process that has been suggested, and more research into some other bit substance. Obviously more drill bits too.

Answer 5

The trick with stainless is to not let the bit spin...and not cut.
Start small and increase the size. Cooling it will help but use cutting oil.

Answer 6

using a tapered HIGH SPEED STEEL ( HSS) bit at low speeds with wd40 sprayed occasionally , dont push it this takes time and patience or many burnt bits, cobalt is a long lastind wood bit

Answer 7

Laser!