CMT 694.021.31 Two-Piece Adjustable Grooving Set, 5-29/32-Inch Diameter, 1-1/4-Inch Bore Heavy duty aircraft aluminum body, 4 carbide knives (19.5x12x1.5mm), 4 scoring knives (14x14x2mm). Manual feed, pins for the automatic positioning of the knives. Spacer ring kit included. Ideal for grooving and creating precise slots from 14mm (9/16") to 39mm (1-35/64") into depth. RPM between 5000 and 8000.