"A final question if I may: Is the purpose of tempering not to bring the RC down to a level that is considered acceptable as being hard enough to be stiff, but not so hard that the steel becomes too brittle for its purpose? So would tempering a hardened alloy that starts out at RC62, not be RC60 or so once it is properly tempered? Or doesn't it work that way?

Best regards,
Bart. "

The stiffness of steel is directly related to thickness. two pieces of equal thickness require the same force to bend R62 or R42.

If you're asking something different it is unclear.