ASME B106.1M Transmission Shafting Sizing Reference Guide
Standard mechanical code for sizing steel transmission shafts subjected to combined torsion and bending.
Standard Scope
Establishes standardized procedures and allowable stress criteria for the mechanical design of circular steel transmission shafting. It details sizing formulas for shafts subjected to torsional moments, transverse bending moments, and axial loads under fatigue loading cycles.
Typical Applications
- •Conveyor roll shaft sizing.
- •Gearbox output shaft mechanical design.
- •Pump spindle shaft dimensioning.
- •Electric motor rotor shaft design.
Key Engineering Concepts
Code Shear Limits
The design allowable shear stress is limited to the lesser of 30% of yield strength (Sy) or 18% of ultimate strength (Su).
Keyway Reduction
Allowable stresses must be reduced by 25% to account for fatigue stress concentration around keyways.
Combined Loading
Sizing calculations must combine steady torsional loads with fully reversed cyclic bending loads.
Engineering Notes & Best Practices
- •Standard rules do not apply to hollow shafts with thin walls prone to buckling.
- •Generous filleted shoulders should be specified to minimize stress concentration.
- •Shaft lateral deflection should be limited to prevent gear tooth misalignment.
Official Standards Reference
Design of Transmission Shafting
ASME standard establishing mechanical sizing rules for steel transmission shafting systems.