Reply by Ruaidhri

For brass and aluminium I wouldn’t bother – have a go at making a tip up from a piece of scrap steel. A couple of minutes on the grinder and the right size hole and you’ll have all you want :-)
Properly tempered and honed you should be able to get a superb finish straight from the tool, and a better cutting edge than from carbide. You can also have one with no rake for the brass, and another with a suitable rake for aluminium.

Cheers,
Ruaidhrí

-- Ruaidhrí, Dublin, Ireland