IDEAL 3/8-in 16 -Step Drill Bit Set ( 1/4-in to 1-3/8-in )

3/8-in 16 -Step Drill Bit Set ( 1/4-in to 1-3/8-in ). The electrician's step bit kit features a durable blow-molded case that securely holds and protects bits. Kit includes four step bits (35-511, 35-513, 35-515, and 35-517). Kit includes drill bits capable of drilling electrical hole size between 1/8 in. and 1-3/8 in. diameter. The innovative step design allows for smooth blending to facilitate stepping through holes. Max operating speed 1500 RPM. Do not use in hammer drills. Apply pressure only in direct line with bit and do not apply excessive pressure