Determination of Y_X acc. to

The size factor ZX takes into account

• The statistical size influence (resulting from the distribution of the weak points in the structure)
• The theoretical strength size influence (caused by the smaller stress gradients for larger dimensions)
• The technological size influence (caused by the forging ratio, unevenness of the structure, etc.)

DIN3990 part 3 sets the size factor YX to 1.0 (all materials for static strength)

Recent research has shown that it can even lead to an increase in the load carrying capacity of small transmissions.

(see THEMIS - FVA Research Project 410 II  (in German) & FVA 410 III (in German))