The X-ACTO #11 classic fine point knife blades are the perfect accessory to a true tool of precision. When elaborate, detailed cuts need to be made, the no. 11 blade is the blade to choose. Because the blade is made with quality sharpened carbon steel, you can make the most detailed, meticulous cuts knowing that the blade can stand up to the pressure. X-ACTO knife blades fit with most X-ACTO knife models. - X-LIFE blades provide superior sharpness and extended life. Each blade is blue oxidized to prevent rust and increase durability. The original X-ACTO knife has been praised for more than 50 years as the standard for precision. Attaining this level of precision, accuracy and reliability starts with supreme quality craftsmanship. X-ACTO knife blades are crafted with quality, carbon steel sharpened for a reliable cut and a strong blade.