If power transmission is carried out by gear coupling, module transmission must be used. Usually the module identifies the type of the gear and it is the ratio between pitch and p. Module changes according to the pitch. Here following the conversion table.
Spurgears with or without hub and racks are manufactured according to DIN 3962, DIN 3963, DIN 3967 regulations. The material used for gear power components is steel C45 according to UNI EN 10083-1 regulations.