Hardened and precision ground. Conform with DIN 6325.
Metric: Sizes 3mm are manufactured from non-hardened silver steel, 4mm and above are high quality through hardened mild steel.
Tolerances:
3mm = +0.002 +0.008
4 - 6mm = +0.004 +0.0012
8 - 10mm = +0.006 +0.0015
12 - 16mm = +0.007 +0.0018