1 inch hole in 2 to 3mm steel

[Ian and Lins]

I want to drill/cut three 1 inch holes in 2 to 3 mm mild steel. How would you advise I do this?

[volks_womble]

Bi-metal hole saw on a drill. Slow speed with a bit of oil added to the cut whilst you are cutting.

Alternately a step dril is a good choice or a cone cutter if the size isn't critical.

Slow and with added lubricant is best tho

Mark

[bigbadbob76]

Probably a bit thick for a Q-max punch.
Hole saw would do the job fine, if you can get a bit of wood behind the panel that would help support it, but don't fret it if not.

[Ian and Lins]

Okay, thanks. I'll give it a go.

[Oldiebut goodie]

I use step cone drills, cheap as chips. I use them to cut holes in mounting plates for my heaters all the time. Mainly metric sizes easily available but imperial can be found.
Like this one:

[clift_d]

Step drill or QMax cutter.

[Ian and Lins]

Step drill I reckon then. I wasn't sure if something like this would cope as the mild steel is nearly 3mm thick (not a vehicle body panel). Thanks for all the advice.

[Oldiebut goodie]

My mount plates are 2mm thick steel. Just ease up on the drilling pressure as you reach the larger bore.