Based on the fixed-end beam calculation. Anticipates that the total circumferential force can only be carried by one tooth.
Allowable load
F all = π c min b w m μ≥ F t
where:
| c min = min (c b , c c ) | minimum tooth allowable stress | |
| b w | operating tooth bearing width | |
| m | module | |
| μ | factor of dependence on the precision degree (table value) | |
| F t | circumferential force acting on the teeth | 
Safety factor
S = F all / F t
Bending factor
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where:
| σ Ab | allowable stress in bending (material property) | |
| r b | speed bending factor (table value) | |
| y b | shape bending factor (table value) | 
Contact factor
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where:
| σ Ac | allowable stress in contact (material property) | |
| r c | speed pressure factor (table value) | |
| y c | shape pressure factor (table value) | |
| 
 | size factor |