Screw - mechanical advantage


A screw is a mechanism that converts rotational motion to linear motion, and a torque (rotational force) to a linear force. It is one of the six classical simple machines. The most common form consists of a cylindrical shaft with helical grooves or ridges called threads around the outside.

The mechanical advantage MA of a screw is defined as the ratio of axial output force Fout applied by the shaft on a load to the rotational force Fin applied to the rim of the shaft to turn it.

The MA can be calculated from the shown formula.

Related formulas


MAmechanical advantage (dimensionless)
ηefficiency of the screw (dimensionless)
rradius of the shaft (m)
llead of the screw (m)