Quoted from Richthofen:I have the dumbest question. How do you tap holes for machine screws? do you need a tool or tools to do this? if you're drilling for a specific screw size, do you use the same size drill bit as the screw you want to insert, or slightly smaller because tapping it will widen it?
You can buy a cheap tap at Harbor Freight. Or you can just use your power drill and make the hole slightly smaller than your screw - black pipe metal is soft. First option is probably "better", second option should work just fine.