1、 preparation before peening
1) the size and surface roughness before spring-shot blasting should meet the requirements of the pattern, except for special instructions (if it is necessary to reprocess the shot blasting surface).
2) the spring shall complete the prescribed heat treatment before shot peening.
3) the non-destructive test of the spring shall be completed before the shot peening treatment, or after the shot peening if there is special requirement.
4) the surface of the spring to be sprayed should be clean, dry and free of oil.
2、 treatment after shot peening
1) the heating temperature of the spring parts shall not exceed 250~E, and the heating temperature of the spring parts shall not exceed 400~C for stainless steel.

2) the spring after shot peening is allowed to be modified mechanically under special circumstances, but only in the direction in which the spring bears the load.
3) no hardness test is allowed in the spring-shot strengthening area of the spring.
4) after shot spraying, it is advisable to remove the residual shot by the method that does not damage the spring surface.
3、 shot peening quality
1) the spring after shot peening treatment shall meet the requirements of the pattern.When the pattern does not give the shot peening strength tolerance, the shot peening strength only takes the positive deviation, its value is 30%, but the minimum value should not be less than 0.8 mm.
2) after shot peening, the surface coverage of the spring-loaded spring shall meet the pattern requirements.When the pattern does not give coverage requirements, the coverage should be greater than or equal to 90%.