Table 12-2-5 Ultimate tensile strength of bronze wire σb
| Material | Silicon bronze wire (from CB 3123-1982) | Tin bronze wire (from CB 3124-1982) | Beryllium bronze wire (from CB 3134–1982) | |||||||
| Wire Diameter/mm | 0.1~2 07 | >2~4.2 | >4.2~6 | 0.1-2.5 | >2.5~4 | >4~5 | state | Before hardening and tempering:HB | After hardening and temperingHB | |
| Soft | 343~568 | >1029 | ||||||||
| Tensile Strength | 784 | 833 | 833 | 784 | 833 | 833 | 1/2 hard | 579~784 | >1176 | |
| Hard | >598 | >1274 | ||||||||
Note: σb in the table is the lower limit value
According to the working characteristics, the load on the coil spring can be divided into
① static load
1.Constant load (Class III load)
2. the load changes, but the number of actions n is less than 104 (Class III load)
②dynamic load
The dynamic load changes, and the number of actions n is greater than 10. The dynamic load can be divided into:
1.Limited fatigue life: cold coil spring action times n1010 ° sub meter load) hot coil spring action times n ≥ 10~103 times
2.Infinite fatigue life; Action times of cold coil spring Y10 coil load 2 action times of hot coil spring n=2 × 10 times;
3.When the coil spring acts n mesons 10 ° -107 times; When the action times n of hot coil spring is between 103-2×10 ° times, it can be designed with reference to the limited or infinite fatigue life according to the service conditions.
