Blue Tornado bits are CNC machined to give a perfect balance and complete smooth finish. All bits are manufactured from 4140 & 5140 steel and are put through a special heat treatment to ensure proper hardness and tensile strength to prevent bending or breaking. A Tungsten micro grain C3 carbide gives the cutter a longer lasting strength that can be sharpened many times over. Craftex Blue Tornado bits also have an anti-kickback design along with an anti-stick coating to decrease friction. Lastly, an automotive semi-transparent finish is added to the bit to give a longer lasting shine. All Craftex Blue Tornado Router Bits and Shaper Cutters are backed by a Limited Life-Time Warranty.