Sherwood: 18.00MM HSS-Co 5% 2 Flute Threaded Shank Long Series Slot Drills Long Series Type S231T - Metric Bright finish. Flute type: 30 helix. Manufactured to BS 122: Part 4: 1980. Metric Tolerances Diameter: ~ up to 3.00. Tolerance: +0.01…View more