The metric bolt thread must be produced to tolerance class "medium" (tolerance class 6g, DIN 13, parts 21- 25), for higher precision requirements to tolerance class "fine" (tolerance class 4h, DIN 13, parts 21- 25). The contact surfaces of the connecting components are essential to optimum functioning and must be manufactured with particular care and precision. To avoid surface seizure, the finish of the contact surfaces should have as low a level of surface roughness as possible.

Back