The document is valid for single- and multiple threaded hobs for the manufacture of worm wheels. The worm wheel hobs for modules till 40 mm were include.
DIN 3973-2:2017 history
2017DIN 3973-2:2017-09 Tolerances of worm wheel hobs - Part 2: Tolerances for deviation of individual parameters
1970DIN 3973-2 E:2017-02 Tolerances of worm wheel hobs - Part 2: Tolerances for deviation of individual parameters
2017DIN 3973-2:2017 Tolerances of worm wheel hobs - Part 2: Tolerances for deviation of individual parameters