Drilling Stainless

Rob

Very easy to drill SS as the secret is in the drilling technique used. Use a good quality HSS drill bit and a 3/8" veriable speed dril motor. 1/4" drill motor is too fast.

Center punch then bump the drill motor trigger to about 1/2 of maximum motor rpm then let off the trigger and at 1/4rpm then bump the trigger back to 1/2rpm, repeat until drilled.

It's varying the rpm with holding the drill at 90� that makes the bit drill easy. To fast and it burns the bit tip, too slow and the bit won't bite.

Once you get the drilling method down, a HSS bit will last about 50 holes in SS being dry drilled.
We found that adding a lubricant, Rapid Tap or Soap, will get about another 10 holes and not worth the extra cost.

Using a drill press drilling SS then Rapid Tap is a great asset. Bar soap thats been soaked in water to make a paste also works well but leaves behind a film that needs cleaned before welding.

We tried the colbalt and titainimum bits with poor results vs using HSS.

A pilot hole diameter needs to be sligthly larger than the finshed hole bit tip size.

T_Bone

I do not think so.

Thanks again
Rob

Good point about the pilot hole--I forgot to mention that. For drilling in thicker material and when the hole size has to be 3/8" or larger, it's also helpful to drill the hole in steps starting with the pilot bit (1/8" or so) and then go up in 1/8" steps. If drilling with a drill press the size step-up "spread" can be larger. I've drilled 1/2" SS, starting with 1/8", then 5/16" and then 1/2". Don't get in a rush and the steady pressure and bit lubricant/coolant makes it work.