Perhaps I am trying to be too clever by looking for inserts for various materials when the Chinese ones might do the job.

The Compact 8 is quite a light lathe, so sharp tooling would stress it less. Quite a few on the Model Engineer side use ground positive rake inserts intended for use on aluminium on steel(s) with good results. May not last as long as on aluminium, but lower cutting forces from the sharp ground edge compared to the usual blunt pressed inserts in negative rake holders.

If you are cranking out production parts & want the most out of hefty industrial machines it is definately worthwhile optimising tooling - but that isn't really what we do in the garage is it ?

Tooling companies work on the basis of an edge life of around 15 minutes in contact. I had several customers who would only make one pass per edge, as the insert may or may not survive two passes at the recommended feeds & speeds on the likes of titanium and nimonic alloys. High value components, so not worth taking risks with tooling.

From memory the only "fancy" insert I have bought for home was a Chinese CBN insert for a boring bar to put a recess in the bottom of a hardened steel Dickson clone QCTP for the Warco to clear a boss on the compound slide. It did the job, but unfortunately didn't live to tell the tale !

Nigel B.