3 Flute: Regular Series - Metric Centre cutting as standard. Offer a combination of advantages achieved with two and four flutes giving profile and peripheral milling capability in addition to slotting and plunging. 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.