Which media is used for shot peening?

Shot peening uses spherical (round) shot, not angular grit. The shape is essential: the sphere compresses the surface through plastic deformation without cutting it, whereas angular abrasive scratches and can damage the surface instead of inducing compression.

The most common media are cast steel shot and conditioned cut wire; specific applications also use glass beads and ceramic shot. The choice depends on the required hardness, the size —linked to the target intensity— and the material of the part.

In double shot peening, the second pass usually uses a finer medium; for carburized gears it may be glass or ceramic, harder than the treated surface.

Shot size and type define intensity and finish; for the detail of each medium and of the process, see the abrasives pages and the introduction to the shot peening process.

CYM defines the right medium according to the component and the desired result.