Drilling Stainless Steel

How to make holes in a not-so-hard metal

- Chip Lawson

For many years I hated drilling stainless steel. It’s hard, it requires expensive cobalt or carbide bits and it takes a long time to drill. In other words, I had many good reasons for feeling this way. However, as it turns out, all of them were based on incorrect information.

First and foremost was the belief that stainless is a “hard” material. Because I thought stainless was hard, I would run my drill at high speed, thinking it would otherwise take forever to complete a single hole. I could not have been more wrong. Thanks to the advice of an exceptional metal worker, I learned the right way to drill stainless with standard High Speed Steel (HSS) drill bits.

Stainless is actually a relatively soft metal, at least in its initial state. What stainless tends to do is “work harden” fairly quickly when heated, and drilling at high speed creates a lot of heat. When stainless steel work hardens, it becomes very hard and extremely difficult to drill.