(Japan)/DIN 861-1980 (Germany), ASME (US), BS 4311: Part 1: 1993 (UK). Tolerances will vary within the same grade as the thickness of the material increases.

* reference (AAA): small tolerance ( or ) used to establish standards
* calibration (AA): (tolerance or ) used to calibrate inspection blocks and very high precision gauging
* inspection (A): (tolerance or ) used as toolroom standards for setting other gauging tools
* workshop (B):