Old Part # SF1218 Old EAN# 07891265400321 12", 18 Tooth, Bi-Metal HSS Hacksaw Blade, This Feature Joins 2 Strips Of High Speed Steel Wires To A Backing Steel In A Solid Phase, Using The Principle Of Solid State Diffusion Bonding, This Generates 170% More Weld Contact Area, Result Is Significantly Reduced Fracture & Breakage, Teeth Develop A Groove In The Very Thin Center Of Backing Material At The Cutting Edge, The Result Is 20% Faster Cutting.