Maximum 12.2 M6 - Iron / unichrome 2.7 × 1.5 (Minimum) 6.1 Unichrome
Maximum 15.4 M8 - Iron / unichrome 3.2 X 2.0 (Minimum) 8.2 Unichrome
Maximum 18.4 M10 - Iron / unichrome 3.2 X 2.5 (Minimum) 10.2 Unichrome
A maximum of 21.5 M12 - Iron / uni-chromium 4.2x3.0 (minimum) 12.2 Uni-chromium
(Maximum) 28 M16 About 10.3 Iron / uni-chromium 5.2×4 (Minimum) 16.2 Uni-chromium