Extension spring

Extension spring,tension springs

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 extension springs

Description of parameters for extension springs

Physical parameters of extension springs

d (wire diameter): This parameter describes the diameter of wire used as material for spring.
De (external diameter): External diameter of a spring concerns both hooks and coils. Tolerance for this parameter is (+-)2%(indicative).
H (Hole): This is minimum diameter of hole in which spring can work. Tolerance for this parameter is (+-)2%(indicative).
Ln (Maximum length): Maximum acceptable extension length for a spring. It is also the maximum extension for static applications. Tolerance for this parameter is (+-)15%(indicative).
Fn (Maximal force): Maximal acceptable force which can operate on a spring. It is also the maximum force for static applications. Tolerance for this parameter is (+-)15%(indicative).
L0 (free length): Free length is measured in spring's free state. Tolerance for this parameter is (+-)2%(indicative).
Nr of coils: This is a total number of coils in a spring - in the picture above it is equal to six. R (Spring rate): This parameter determines spring's resistance, while it is working. It is measured in 1 DaN/mm = 10 N/mm. Tolerance for this parameter is (+-)15%(indicative).
L1 & F1 (length under charge F): The charge F1 at length L1 can be calculated using the equation : F1 = Fn - R(Ln-L1). Equation derived from the previous for calculating L1 = Ln - (Fn-F1)/R.
Hooks: Extension springs with german hooks are produced in two versions: with hook positions of 0 degrees and 90 degrees as shown in the picture above.

Materials of Extension spring

A (Music Wire): Steel that conforms to the DIN 172233 class C1 standard.
I (Inox steel): Inox 18/8 mark Z10 CN 18.09.

Tolerances of Extension spring

maximal force: Tolerance for the maximal force is (+-)15%(indicative). maximal length: Tolerance for the maximal length is (+-)15%(indicative).
Spring rate: Tolerance for the spring rate is (+-)15%(indicative).

>>Tension springs

Xiamen Shuangyuan Springs Co., Ltd copy right @2006-2008
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