"Dave Plowman (News)" wrote:
In article ,
Lurch wrote:
Many people of course won't have a small enough masonry drill, as this
size is probably rather small for general use.

What size? If the hole in the box is smaller than 5.5mm then the masonry
bit will make it 5.5mm, or have I misunderstood what you were saying?

I was just sort of rambling that perhaps most uses of wall plugs will
involve a larger size - fixing shelves etc. So all may not have small
enough plugs and a suitable drill lying around.

IIRC, the standard size hole in a metal box is 4.5mm.

So use a 4mm or 4.5mm drill and yellow plugs. No chance of blunting
the masonry drill on the box then.

I fix lots of quite heavy stuff with 4mm screws in yellow plugs, 4mm
screws are well strong enough (about 8 in old parlance) and they are
much more secure in yellow plugs than in red ones.

--
Chris Green