RECIP BLADE 24T X 4in. BI-METAL CONTRACTOR 3/4in. W .035 THICK 1/2in. UNIV SHANK - CONTRACTOR SERIES COBALT BI-METAL RECIPROCATING SAW BLADES. LASTS 10X LONGER. UNIQUE NITRO HARDENING PROCESS FOR OPTIMAL STRENGTH AND BLADE LIFE. FUSED COBALT TEETH. 5 PERCENT COBALT TEETH FUSED TO FLEXIBLE SHATTERPROOF BODY FOR RUGGED CUTTING. WHEN COMPARED TO STANDARD CARBON ALLOY BLADES. 1/2in. UNIVERSAL SHANK FITS ALL POPULAR RECIPROCATING SAWS. THIN SHEET OR TUBE FERROUS AND NON-FERROUS METAL CONDUIT.