I'm thinking hole sizes from around 8mm - 25mm. I have a decent quality, newish, floor standing pillar drill. What are the best type of drill bits to use and technique of drilling, speed to run bits, will steel heat up, deform? Cutting fluid type, using it, better to drill smaller hole first, then larger? " drill smaller hole first, then larger ", speed to drill at? This in relation to different drill sizes? Will I get a nice clean hole? I'm drilling a 300 x 300mm sheet. Any help advice appreciated. Cheers.