They are densely filled for high aggression and long tool life and feature a 3/8 in diameter steel stem with a flat foruse in a collet or end mill holder.008 in Fila Weiler crimped wire Bore-Rx brushes are designed forautomated use in CNC machining centers and dedicated equipment. Since they caneliminate manual deburring operations, these internal brushing tools help to improve part to part consistency and reduce direct labor costs..