On Fri, 07 Feb 2020 11:12:11 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
The Other Mike wrote:
550W correctly reduced in speed via a pulley system and preferably a
steel geared gearbox will mean, at least with a correctly sharpened
drill bit, you'll easily be able to drill 1 inch diameter holes in mild
steel plate. Restraining the item you are drilling could be the bigger
issue.

A 1" twist drill? Crikey. ;-)

I have a set of 'blacksmiths drill bits' that go up to that size
(diameter g). I mainly use them when counter boring softer materials
on the lathe as they are quicker than say a 13mm bit then boring bar.

Cheers, T i m