Blades are bi-metal technology with a high-speed steel cutting edge that stays sharp longer. Fits most standard utility knives and are flexible to last longer.
IRWIN 1774106 Utility Knife, 3-1/2 in W Blade, Carbon Steel Blade, Comfort-Grip Handle, Blue/Silver/Yellow Handle
IRWIN 2088100 Utility Blade, Bi-Metal/HSS, 2-Point
IRWIN 2014097 Utility Blade, 2-3/8 in L, HCS, 4-Point
IRWIN 1768772 Construction Chisel, 1/4 in Tip, 3-5/8 in OAL, HCS Blade, Ergonomic Handle