IVY Classic 28718 H1218C 12-Inch 18 TPI Metal/Plastic Cutting Hacksaw Blade, Bi-Metal, USA, 1/Card Cuts metal over 1/4-inch and plastic, Cobalt Advantedge (Registered Trademark) Bi-Metal blades with 8% cobalt 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, 12-inch length x 1/2-inch width x .025-inch thickness