IVY Classic 28536 P218C 1-3/4-Inch 18 TPI Metal Cutting Bayonet-Shank Jig Saw Blade, Bi-Metal, USA, 1/Card Cuts metal 1/16-inch - 1/4-inch, Cobalt Advantedge (Registered Trademark) Bi-Metal with 8% cobalt matrix II alloy-steel cutting edge retains hardness Cutting edge electron welded to flexible, alloy-steel back for consistent quality Precision milled shatterproof teeth with Rockwell Hardness of 65-67 HRC. Made in USA, 18 TPI, 1-3/4-inch length, 1/4-inch width x .035-inch thickness