On 2008-07-29 09:25:06 +0100, "Dave Plowman (News)"
said:

In article 488ecff2@qaanaaq,
Andy Hall wrote:
which the screwdiggers seem to produce the right size of hole for the
plugs the cutters produce.

The snag with those is I may not always want a through hole - I've used
plugs to replace old screw holes etc rather than filling. I do have some
of those drills and they're very slow at making the countersunk hole.

Have a look at Axminster part number 300532. This is a set of plug
cutters and shaped drills for the holes which match properly. You
can adjust the drills such that the front thinnest part is very short
and not a through drill.

Indeed you can - I've got several of this sort of combination bit and
forgot you can adjust the position on the drill. But I'm actually ok for
hiding screw heads - I have a router cutter which is the right size and
works ok in a drill. It's the larger sizes that are more of a problem.

What I think I need is Forstner bits designed for the job. I don't have a
big selection of these so perhaps need to see if there is a metric one
which gives the correct hole for an imperial plug cutter - or vice versa.
Lip and spur drills tend to pull themselves in rather too easily if you're
working with a hand held drill.

You shouldn't need to do this. Are you drilling on a drill press or
in situ? If it's the latter then you could fit a small portable
stand/depth stop to the drill to prevent it from pulling in.