For 5L snap-back 1L, 4L or 5L and standard K12L arbor Y Designed to be used for cutting mild-steel, stainless steel, copper, brass, aluminum, plastics, wood, and composition board Lenox 1771952 Hole Saw Features 3/4-Inch Steel Wood and Metal Crown Slot Speed Up to 2x Improved Tooth Geometry Cutting Life on Metal, Thin Kerf Design, and an Advanced Coating to Improve the cutting process. Includes (1) 1771952 3/4-Inch Diameter Bi-Metal Steel Hole Saw for long life, fast cutting, and improving cutting or job site speed.