Made from carefully selected, age-specific steel. Particularly wear-resistant due to controlled hardness (HV 800). Carefully hardened and hand-ground. Includes the manufacturer's test protocol, traceable to national standards: Each gauge is individually marked with an identification number. The actual deviation from the nominal size is noted in the protocol. The absolute actual dimension is thus known. Tolerance class 1 for the verification of test masses, measuring instruments, and for the calibration of length measuring devices, as well as for standard tasks in the measurement room.