The torsion spring is divided into single torsion spring and double torsion spring. The spring is usually inserted into the pin or shaft. When external force is applied, a torsion force is generated according to the shaft center of the spring to make the spring coiled tightly or loose.

Double - twist spring is divided into external double - twist and internal double - torque spring.

The loops are either closely encircled or separately encircled to allow for a load of torque (at right angles to the spring axis).The end of the spring can be wound into a hook or straight twist arm.The following is the necessary information of a torsion spring:

(1) free length.

(2) control diameter :(a) outside diameter, (b) inside diameter, (c) inside diameter of casing, or (d) outside diameter through round rod.

(3) steel wire size "wire diameter".

(4) materials (type and grade).

(5) winding number :(a) total winding number and (b) right or left turn.

(6) torque: the number of pounds deflected to an Angle.

(7) maximum deflection (Angle from free position).

(8) terminal form.

Torsion Spring is a variant of the Spring, from single Torsion to double Torsion, and various Torsion bar deformation, depending on the design.

Torsion Spring is a kind of complicated design principle in all Spring categories, and the type changes are quite lively. Therefore, the theory involved in the design is also the most annoying.Therefore, the design is also difficult to master.