The basic spring parameters of the spring:
1. Spring wire diameter D: wire diameter of spring.
2. The outer diameter of the spring D2: the maximum outer diameter of the spring.
3. The inner diameter of the spring D1: the smallest outer diameter of the spring.
4. The middle diameter of the spring is D: the average diameter of the spring. Their calculation formula is: D= (D2+D1) +2=D1+d=D2-d
5, pitch T: except for the support ring, the distance between the two adjacent circles of the spring corresponds to the axial distance on the middle diameter of the spring, and is expressed by t.
6, effective circle number n: the number of circles that the spring can keep the same pitch.
7, the number of supporting rings N2: make the spring work in the J, ensure the vertical axis of the axis and manufacture, often the two ends of the spring tightly. A tight loop number only
The supporting function is called the supporting ring. Generally, there are 1.5D, 2D and 2.5D, and 2D is commonly used.
8. The number of the total circle number n1: and the sum of the support circle. That is, n1=n+n2.
9, free high H0: the height of the spring without external force. From the lower L: H0=nt+ (n2-0.5) d=nt+1.5d (n2= 2)

10, the spring expansion length L: the length of the wire required for winding the spring. L hook N1 (1D2) 2+n2 (pressure spring) L=J1D2 n+ hook expansion length (pull spring)
11 'spiral direction: left and right spin, commonly used dextral, the drawings do not indicate the general use of dextral.
12, spring winding ratio: the ratio of medium diameter D to steel wire diameter D.