4 Flute: Regular Series – Metric | Centre cutting as standard. For maximum strength when milling harder materials where rapid swarf removal is not needed. 4 flute milling cutters have one of the strongest tooth structures available in solid cutters. 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.