On Fri, 23 Jul 2010 05:32:56 -0700 (PDT), Andy Dingley wrote:

On 23 July, 13:09, PeterC wrote:

For some screw-heads a 20p piece is almost a perfect fit.

http://www.leevalley.com/US/wood/pag...=1,43411,43417

Not bad for range, but a constant-diameter polygon has less radius of
curvature so is better in a slot. It's also more common.
--
Peter.
The gods will stay away
whilst religions hold sway