Force to Achieve Torque

[macvicar]

Does anyone know if there is a formula to determine the manual force required on a wrench to tighten a fastener to a specific torque ? I understand that variables such as bolt size, materials used, hand position on the wrench etc. all play a role, but is there a rule of thumb ?

Thanks

Jeff

 

[BillBirch]

Divide your required torque by the length of your wrench and you have the required force.