Screw - torque

Description

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 rotational force applied to the screw is actually a torque Tin=Fin*r. Because of this, the input force required to turn a screw depends on how far from the shaft it is applied; the farther from the shaft, the less force is needed to turn it.

The torque can be calculated from the shown formula

Related formulas

Variables

Foutthe force done on the load (N)
Tinapplied rotational torque (N*m)
πpi
ηefficiency of the screw (dimensionless)
llead of the screw (m)