6. Surface finishing

6.1 Shot-blasting

Shot blasting consists of projecting very hard, spherical particles onto the surface of the product to be treated. Their diameter ranges from 0.15 to 0.6 mm. The type and speed of particle blasting, as well as the duration of the blasting operation, must be optimized according to the desired result. After shot-blasting, the surface layer of the treated product is work-hardened to a thickness of a few tenths of a millimeter (up to 0.3 mm). The resulting surface compression has a positive effect on fatigue life.