|Limit of strength|
|A1, A2, A4||50||M 39||500||210||0,6 d||500|
|70||M 20||700||450||0,4 d||700|
|80||M 20||800||600||0,3 d||800|
Bolts - hexagon, cylindrical and hexagon socked head bolts diameter from 5mm have to bemarked out in accordance with the validation system, see. Example above. Marking can be done where the screw head is. It must contain class and strength of steel (designation of origin). Anyadditional markings shall not conflict with standard markings.
Nuts - with a diameter from 5 mm is specified as a group of steel, strength class (if required) with designation of origin, if it is technically possible.