For crossed axis helical gear designs where a worm meshes with a cylindrical worm wheel made of plastic, the static analysis considering fracture or yield point of tooth tensile/bending strength often results in unrealistically low safeties. In practical experience, the proof of tooth shearingis a more important design criterion. This calculation is now available in KISSsoft (module ZE4), carried out according to literature references. The same calculation method is also described in the future Standard VDI 2736 and recommended for application.