Blades Offer a Super-Sharp High Speed Cutting Edge. Bi-Metal Blades Combine the Toughness and Shock. Resistance of an Alloy with the Cutting Ability of High Speed Steel. Outlasts Conventional Blades up to 3 Times Longer. High Resistance to Breaking & Requires Fewer Blade Changes. High Speed Saw Blades Can Be Used In Any Hack Saw Frame.