Key Strength Calculations

To determine the torque capacity of key..

• h = Depth of key (m)
• r = Radius of shaft (m)
• Le = Effective Length of key = Straight Length (m)
• b = Breadth depth of key (m)
• T = Torque capacity of key (N.m )
• s_c = Allowable compressive strength of key (N/m²)
• t = Allowable shear strength of key (N/m²)

T = t .b . Le .r.....based on shear

T = s_c .h . Le . r / 2.....based on compressive strength

ISO straight sided Spline Capacity

• r = Mean radius of spline (m)
• n = Number of splines
• Le = Effective Length of spline = Straight Length (m)
• d = Depth of Spline (m)
• T = Torque capacity of key (N.m )
• s_c = Allowable compressive strength of key (N/m²)
• t = Allowable shear strength of key (N/m²)

T = s_c . n .d . Le . r.....based on compressive strength