Brocha giratoria hexagonal HSS tamaño métrico broca perforadora herramientas de perforación vástago 12,7 mm
About processing, 1, use drill bit to make a hole, like 6mm hexagon, you should use drill bit to do a hole 6mm. 2, use hexagon punch bit 6mm to working in the hole, at first, cutting feed slowly, like 300-500 is ok.