As you say we dont crank out production parts in the garage, everything is normally a bespoke 1 off, although at the moment I am machining a batch of 3 identical units - end cans for the KH 400 Spannies.

To be honest the inserts I usually get from the autolumble work well on all materials that I work with in the garage. Those inserts look remarkably similar to the Chinese ones on E Bay, so will probably give them a go.

Biggest mistake I used to make machining stainless was to try and cut too much, and too fast, which of course just work hardens it which wrecks the cutter, smaller cuts, lower speeds - just takes a little longer !