The difference with shot blasting:

Shot peening utilizes compressed air to accelerate and eject media through the nozzle at high speed. As a strengthening process, it offers the distinct advantages of high adaptability and process stability. In contrast, shot blasting typically employs a high-speed rotating impeller to propel media. While shot blasting is less adaptable and stable for precise strengthening, it is significantly more efficient and requires fewer specialized processing conditions, making it ideal for high-volume surface cleaning.

The difference with sandblasting:

Shot peening and sandblasting both utilize compressed air to propel the media (shot or sand) through a nozzle at high speeds. This media impacts the workpiece surface to achieve the desired process effect.

The media used for shot peening is typically spherical or quasi-spherical such as steel, stainless steel, glass or ceramic shot. This is generally used for strengthening components (improving fatigue life) or surface finishing to create a matte effect. In contrast, the media used for sandblasting is angular, such as steel grit, corundum, silicon carbide, or walnut shells. These angular particles are primarily used for surface cleaning, texturing (to increase roughness) and stripping coatings.