Constructed of hardened heat and abrasion resisting high speed steel teeth. With a tough alloy body and cap, giving exceptional strength, durability and shatter resistance. Designed for use with battery operated power tools, our Bi-Metal Cordless Smooth Cut hole saws will cut twice as many holes as the equivalent standard hole saw per battery charge. The complete hole saw assembly includes arbor and pilot drill. Its flared base cap limits cutting depth to ½”.