Sharp tough bimetal blades. Will not shatter. Easily cuts steel, stainless steel, nail-embedded wood, hardwood flooring, reinforced bar, conduit, cast-iron, and pipe. Standard 1/2" shank. Model No. S318RC thru S110R have 1 blade per card and model No. 456R thru 118R have 5 blades per clamshell, and model No. OSB656R thru OSB818R have 50 blades per bulk box.