The 50 Pack of LENOX Gold Utility Knife Blades features high-speed steel construction and a titanium coating that retains its edge longer than standard utility blades. Bi-metal construction allows the blades to stay strong without shattering even when bending and flexing. The 4-notch design allows these blades to cut deeper in drywall insulation flooring roofing and more. These blades fit all standard utility knives.