2 Flute: Regular Series - Metric For optimum performance and maximum swarf removal when plunging, slotting and routing in light alloys, brass, aluminium, non-ferrous and other soft materials. Manufactured to Works Standards. Metric Tolerances Diameter: Over 1.00 ~ up to 6.00. Tolerance: +0.000, -0.050. Diameter: Over 6.00 ~ up to 25.00. Tolerance: +0.000, -0.080.