Metric – 12mm/Shank Diameter. | Produces closed slots for woodruff keys to DIN 6888. For milling structural, carburizing and heat treated steel up to 900N/mm2. Manufactured to BS 122 : Part 4 : 1980. Made to DIN 850. Shank to DIN 1835/D. | | Metric Limits of Tolerances: | Diameter +0.000 -0.127. | Width | 2 up to 4: – 0.014 -0.028; | 4 up to 7: – 0.020 -0.038; | 7mm up: – 0.025 -0.047. |