mark where the hole is togo, centre punch position. THIS STOPS THE DRILL SKIDING and marking your workpeice. use a centre drill, if needed drill a smaller (pilot) hole 1st then use you correct drill size.
you can use HSS or Carbide. make sure they are sharp.
use coolent, AND most of all dont run the drill 2 fast, start of slow and increase the speed youll know when its cutting well.
I've never used a carbide tip to drill stainless. I've used tipped tools for turning, but never drilling. I can't imagine what they must cost! Do as Bassrock says. Use a good quality HSS drill, Dormer or similar & you should have no trouble. Use a good cutting fluid such as Supercut or Rocol,pilot drill first...No Probs !!
Increase angle? I've always found 120 fine & surely no need to reduce land if pilot drilled first. Cobalt drills? Never found any advantage over HSS in S/S. I'm sure everyone has their own opinions, so the more replies you receive, the more confusing the problem will become. Sorry Mate....Good luck. :O
I've had another thought....After decrying carbide tipped drills, has anyone tried those Bosch "Multi constuction" bits? They are supposed to drill any material, as they have a sharpened carbide tip. I know they work fine in brick etc., but maybe they would work in S/S. Has any one tried them?
I've never found stainless a problem to work with (not as bad as people make out),but spring steel is another matter altogether. It usually needs to be annealed by heating & then allowed to cool slowly. It can then be drilled just like mild steel. Now it needs to be hardened again by heating & quenching rapidly, but this makes it brittle, so it needs to be tempered. Do you really need to drill it ?