Clevite coated H-Series main bearings were developed primarily for NASCAR racing, but are also well-suited to other types of competition engines. They are especially good for engines that run at medium-to high revs. They have steel backings with carefully selected overlays and a high crush factor, plus a medium level of eccentricity. These H-Series bearings feature Clevite's exclusive TriArmor coating, industry's only moly/graphite treatment. The sophisticated blend, in a low-friction PTFE polymer base, offers extraordinary protection and lubricity. Clevite's H-Series bearings have enlarged chamfers at the sides for greater crank-fillet clearance and are made without flash plating for better seating