Morse, CTD315 (167475), 50mm diameter, carbide tipped hole cutter is designed for cutting precision holes in thicker sheet metal and plate applications. Ground tooth profile provides clean, fast cuts. Step center pilot drill reduces "break through" impact. Sholdered cutter body prevents pass through. Grooved gullet directs chips up, and away, from the cut. Ejector spring aids in slug removal. One (1) cutter per box. Replacement parts, CTDP (16700) pilot drill and CTDS (167017) ejector spring.