Well, that is a tough question to answer. A Cleveland HSS blank from their heyday would undoubtedly be in the mid to high 60's Rc. However, around a decade or more ago they started having even their flagship Mo-Max HSS made in Mexico, and today I believe it's made in China. Anything goes when QC isn't being monitored like it should. There are varying grades of HSS also. If you want a really hard one look for something like T15.