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Cryogenic bits - the Norseman CN-Tech bits are the ones I am most familiar with, The bits get a nitride coating and then cooled to -300F. They become harder and stronger and less brittle.

For example, I was working on a rusty steel frame that was used for hay feeding. There were lots (about 120) of 3/16" holes since there were lots of rivets to install. I tried a couple of HSS and TiN coated bits - they cut ok. I switched to the cryo bit and finished the remaining 100 hole with greater speed - holes took about 75% or less time to drill. All holes were using a hand drill with yours truly standing in awkward positions. After finishing that project, I used the same bit for 200-300 holes in steel, still going strong and no need to sharpen.