Originally Posted by
costina
Broching is done by a stepped tool which is pressed into a bored hole to almost chisel a step into the hole to make a keyway or splines.
That's the simplest way i can explain. I done it many years ago when in engineering.
you can spark erode too I believe
I think it was what you mention spark erode he was explaining he must've mentioned both ways the chemicals would be for cutting was a while back lol this is his company makes some pretty cool stuff
http://www.alloceans.co.uk