However, shot peening and sandblasting do differ in a few respects.
Sandblasting, obviously, utilizes sand as an abrasive material, while shot peening uses round metal, glass, or plastic particles to alter metal surfaces. Additionally, the goal of shot peening and sandblasting are slightly different. While sandblasting is used to smooth the surface of a material, the goal of shot peening is to add a compressive residual stress layer to a material.
As the metal, plastic, or glass particles collide with the metal surface at high speed, they create deformations rather than stripping away material like with sandblasting, creating less dust and removing less material from the surface.
Shot peening machines like air blast systems and centrifugal blast wheels help to maintain the strength of a component that is subject to wide variations in stress. When an air blast system is used, the particles are forced through a nozzle using compressed air at a high pressure. This nozzle is pointed directly at the part being peened while the machine is on.
In centrifugal blast wheel equipment, a high speed paddle wheel swings towards the part being worked on. When the shot particles are added to this wheel, it hurls them with a high level of force towards the component, accomplishing the same effect as an air blast system.
There are a variety of materials that can be used for the shot peening process, including cast steel, ceramic beads, glass or rounded cut wire. Cut wire is a popular choice because it does not lose its roundness when used on a part.
Industries like automotive, aerospace, renewable energy and medical all use shot preening machines to clean and maintain critical parts for their equipment. If a car is being restored, for instance, parts can be disassembled and treated with shot peening machines to remove rust and smooth them out, adding strength.
Machines that are used for shot peening process can be purchased in styles and sizes that are uniquely suited to meet the scale of large and small industry jobs. Some systems come mounted on tables so that parts can be securely held in place while the machine is being used.