These IRWIN Bi-Metal Utility Knife Blades have a welded, bi-metal design for a sharp edge and flexible body and maintain sharpness up to 3 times longer than traditional carbon blades. A shatter-resistant design adds safety. Each utility blade fits most utility knife handles.
The Irwin Blue Blade Bi-Metal Utility Blade uses bi-metal technology to create a blade with superior performance and shatter-resistant ruggedness. The spring steel body has superior flexibility to resist breakage under stress, and the high speed steel cutting edge resists dulling. This back includes 100 blades.

Irwin Industrial Tools 2084400 Bi-Metal Blue Blade 100 pack. The Irwin bi-metal utility blade is a revolutionary bi-metal utility blade. It's bi-metal technology sets new standards of performance, by providing a blade that stays sharp three times longer than the conventional blades.