When working with hardened steel, you have to use special metal drill bits in order to penetrate the steel. If you use the wrong drill bits, you can damage the bit, the steel and the drill.
Metal Drill Bits for Drilling Hardened Steel
The most common metal drill bits that are used to drill into hardened steel are made out of high-speed steel (HSS). The reason HSS bits are most commonly used is because of their own hardness and durability. You can get metal bits made out of cobalt steel or Tungsten carbide, but these are more brittle than the HSS bits and can break easier.
Tips on Drilling Metal
Besides using the proper metal drill bits, there are a few other things that you can do to make your drilling go smoothly.
When drilling metal, there is always a buildup of heat that can dull the drill bit, making it harder to penetrate the metal completely. There are a couple of things that you should do to make sure that the heat is kept low.
Drilling at a lower speed will keep the heat down, since there isn’t as much friction occurring. Using a lubricant will also lower the friction and help keep the heat down.