I wish I had more time in metallurgy , we have a forge and kiln. Casting welding etc. however any time I need to harden steel I follow standard practices . I just follow the advice of those who have been there before me

My background was medical polymers

replacement Plane blades I've used and like are Hock and Pm-v11

the standard blades from Lie Nielsen and Woodriver are great

For Chisels I spend extra on Blue Spruce tools

They use an opitical flatness standard I'm familiar with in my R&D career

Mostly because I'm not spending an afternoon lapping on a diamond plate

nobody's got time for dat