This pack of 50 pieces of Irwin Bi-Metal Trapezoid Knife Blades combine the best of two metals electro-welded together. To fit all types of Stanley, Stanley FatMax, Delphin, Allegro, Shark and other makes of tradesman's hand tool they are used by professionals in industry, flooring, roofing, warehousing, subcontract packing, DIY, crafts, graphic arts.

The edge of the blade is made from high speed steel, which is much resistant to breakdown than standard carbon steel blades due to the alloying elements within the steel.

These blades have been shown to last up to three times longer in user trials on plasterboard, drywalling, roofing, insulation, flooring and other heavy-duty materials.

The bulk of the blade is made from spring steel, which can resist pressure applied from the side without snapping.The safest blade to use is generally a sharp one - as it takes less effort to cut, and therefore greater control can be maintained.

This blade stays sharp up to 3 x longer than standard blades. The high-speed steel edge is heat treated to greater hardness for longer life and edge sharpness.

These blades are supplied in a safety dispenser.