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.