In article ,
John Rumm wrote:
Well then that would work, no tapping required. Be sure to make a good
indent with a centre punch in the pipe before you start to drill. The
drill tends to wander on SS, esp. on a convex surface.

It would be worth buying a centre drill for starting the holes...

http://www.ebay.co.uk/itm/RDGTOOLS-S...item43acd35fc6

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.

A decent centre punch should do the job - perhaps with a support down the
tube inside to avoid damage.

--
*Lottery: A tax on people who are bad at math.

Dave Plowman London SW
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