On 23/09/2013 18:28, Andy Burns wrote:
John Rumm wrote:

On 23/09/2013 14:47, Dave Plowman (News) wrote:

John Rumm wrote:

It would be worth buying a centre drill for starting the holes...
http://www.ebay.co.uk/itm/290662342598

I remember dad having a set of them, but those were rusted to hell 30
odd years ago.

I'm not sure how much use those are in a pillar drill - they're more
designed for use in a lathe. And tend to be made out of rather softer
steel than ordinary twist drills - so go blunt more quickly.

IME they are ok as long as the quill is not too sloppy. Even then, if
you adjust the table so you don't need to use the drill at full depth
they usually give a marked improvement on the smaller twist drills.

They don't seem to come in metric sizes (or at least not a full range),
so e.g. a 1/4" centre drill would only be useful as a pilot hole for a
7mm hole for the rivnut.

The size is not that important - its just to get a hole started in the
right place. You don't have to drill that deep with them.


--
Cheers,

John.

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