This bi-metal speed slot hole saw is designed with T3 technology. There is increased wall thickness, larger and sharper teeth, and fast, easy plug ejection with the speed slot. For use with 5L snap back and 1L/4L/5L standard arbors, it measures 1 1/8 inch/28.6 millimeters in diameter. Measurements for pipe tap applications are 1 inch/25.4 millimeters, with a pipe entrance of 3/4 inch/19.1 millimeters.