>Wouldn't an easier solution to your 25mm dia Ali bits you're painfully cutting out if plate have been to buy 25mm round Ali, cut to length, mark the centre and drill?

Maybe, but I don't have a metal saw - at least this way I can be sure that each spacer is an identical height - buying stock cut to length is always a bit hit and miss... The guide bit drills the centre hole too! Bonus.

Yep, it's a pain - but on the next batch I'm going to try drilling a guide hole straight through, cut from one side, flip, re-align and from the other side. It's the swarf not rising cleanly out of the cut after 15mm or so of depth that's making this job a pain - flipping the piece should solve the problem. I can only hope!

Cheers.

w./