Sherwood: 1/2" HSS-Cobalt 3FL Sc/Sh Slot Drill Regular Series Type 5321T. Bright finish. Flute type: 30 helix. Manufactured to BS 122: Part 4: 1980. Inch Tolerances: Diameter: up to 1". Tolerance: +0.0025, -0.0005. Diameter: Over 1". Tolera…View more