Shot Peening

Shot peening is a method of cold working the surface of a metal components by the impact of a stream of spherical particles. The shot is propelled at the components surface by means of air or discharged by centrifugal force from an impeller wheel. When the shot particles strike a components surface, they cause the surface to plastically deform, with hammer head like impressions into the surface.


IST’s shot peening service is unique - it is one of its kind, dedicated specifically to enhancing the fatigue performance of springs.  Over 40 years of research and experience of shot peening spring and non-spring components ensures that we use the optimum process parameters to achieve the best performance for your springs.



  • Improves the life of the component

  • Improves compressive stresses

  • Removal of burrs and metal flashing

  • Removal of scale

  • Reducing the risk of surface cracks

Our service includes steel, glass and ceramic media, spring wire / section sizes from 0.3mm (0.012″) upwards plus full technical back-up all rigorously quality controlled to ISO 9001. Our post peening services include:

  • Low temperature heat treatment

  • Temporary corrosion protection

  • Pre-stressing to stablise dimensions

  • Acid dip and passivation for stainless steel springs

  • Fatigue testing to validate the efficiency of the shot peening process

  • Duplex peening and strain peening available for suitable applications

Pre Shot Peened
Pre Shot Peened
press to zoom
Post Shot Peening
Post Shot Peening
press to zoom

Goodman diagrams showing the benefits of shot peening, with the life of the spring in its as-received condition expected to achieve 100,000 cycles in comparison to a shot peened spring exceeding 10,000,000 cycles.