advice for cutting hole in s. steel sink / any1 used Punch?

[snadge]

I have got a 35mm punch/sheer for the tap (faucet) hole itself from IKEA, but im wanting advice about cutting the 10mm hole for the punch's bolt to get through, ive bought a 10mm BOSCH drill bit as it says 10mm in the punch instructions... this is my first time cutting through a stainless steel sink so want to get as much advice as possible before i go ahead...

also,
the punch diagram shows the punch teeth coming up from bottom, well i think it might be best the other way incase any edges are bent they would be bent down out of the way of the sealer/bit that the tap sits on as this is exactly 35mm in diameter aswell so any bent up edges would stop it sitting flat/flush... has anyone got any experience with these punches?

thanks in advance

 

[1john]

use HSS bits, start with a 2mm one and go up in 1mm increments until you get to 10mm. I like a fast speed with low pressure.