# Torsion spring

1. wire diameter as below:

0.1mm – 3.0mm wire

3.1mm – 12mm wire

12.1mm – 65mm wire

2. ISO9001:2000 certified

3. Competitive price and fast delivery

4. These springs are manufactured by fully automatic spring making machine,low cost

### Description of parameters for Torsion springs

### Physical parameters of torsion spring

**d (wire diameter)**: This parameter describes the diameter of wire used as material for spring.

**Dd (Shaft)**: This parameter describes maximal diameter of spring shaft in industrial applications.Tolerance for this parameter is (+-)2%(indicative).

**Di (internal diameter)**: Internal diameter of a spring. It can be calculated by subtracting the wire diameter multiplied by 2 from the external diameter of a spring. Internal diameter in torsion springs decreases while the spring is working even up to shaft diameter. Tolerance for this parameter is (+-)2%(indicative).

**De (external diameter)**: External diameter of a spring. It can be calculated by adding the wire diameter multiplied by 2 to the internal diameter of a spring. External diameter in torsion springs decrease while the spring is working. Tolerance for this parameter is (+-)2% with tolerance (+-) 0.1 mm

**L0 (Free Length)**: WARNING: Free Length decrease while spring is working. Tolerance for this parameter is (+-)2%(indicative).

**Ls (Leg Length)**: It is the distance from the center axis of the coil body to the end of the torsion springs' leg. Tolerance for this parameter is (+-)2%(indicative).

**An (Maximum angle)**: Maximum acceptable rotation angle for the spring in degrees. Tolerance for this parameter is (+-)15 degrees (indicative).

**Fn (Maximum force)**: Maximum acceptable force that can operate at the end of torsion springs' leg. Tolerance for this parameter is (+-)15%(indicative).

**Mn (Maximum torque)**: Maximum acceptable torque (Newton * mm). Tolerance for this parameter is (+-)15%(indicative).

**R (Spring rate)**: This parameter determines spring's resistance, while it is working. It is measured in Newton * mm / degree. Tolerance for this parameter is (+-)15%(indicative).

A1 & F1 & M1: (angle at torque or force) The following equation calculates the angle as a function of the torque: **A1 = M1/R**. In order to calculate the torque from the force, we use this equation: **M = F*Ls**

**Leg position**: There are 4 types of torsion springs' leg positions: 0, 90 ,180 or 270 degrees (see picture above).

**Helix direction**: A right-hand-wound spring loads in a counter-clockwise direction. A left-hand-wound spring loads in a clockwise direction. Both types are available in all sizes.

### Materials of torsion spring

**I (Inox steel)**: Inox 18/8 mark Z10 CN 18.09.

### Tolerances of torsion spring

**Leg position**: (+-)15 degrees

**Leg Length**: (+-)3 %

Address: Defenghang Industrial Zone, Dongfu Town, Haicang District , Xiamen Fujian, P.R.China

Tel: +86(592)5254186 +86(592)5289710 Fax: +86(592)5513310

Email: shuangyuan@springinchina.com rosecn888@gmail.com