cutting holes in the FRAME?

what type of tool can cut or drill a hole thru a frame? besides a plasma cutter. im looking for perfect round holes. thanx...im thinking maybe a uni-bit.

try a hole saw it might work it comes in diff. sizes 3/4"-4"

unibit will only do up to 3/4 hole.

i have hole saws from 1/2-1"....just trying to re-route my air line thru my frame! but i'll give the uni and hole saw a try thanx guys