I've never cut Hardox with mine so can't comment on that. I think the general rule with holes is that the diameter needs to be at least twice as big as the metal is thick to get something like a decent hole. I have been known to plasma the hole to get the position and then run a punch through it to true it up.I have seen a few swiftcut for sale locally one has a 200amp plasma with it. Does hardox cut ok and not chewy? Bolt holes not to tapered?