TomD
A carbide drill bit is capable of drilling hardened metal. But whether it would do a Hock I don't know. We use carbide tooling for stuff like cutting allen keys into screw drivers, rather than buying fitted screw drivers. But those are probably hardened into the 50s. Still small solid carbide twist drills are fairly cheap, so why not give it a try. It might also be worth using if you try one of the differential methods of drawing the temper, since you won't be guaranteed an annealed result.