A toolroom receives an order to produce a master gear for internal use. The machinist must grind the teeth to a tolerance defined in DIN 3970. The PDF provides:
DIN 3970 consists of several parts specifying dimensions, tolerances, and inspection methods for (both go and no-go gauges) used for involute splines according to DIN 5480, DIN 5482, and older standards. din 3970 pdf