What's the difference between sandblasting and shot blasting?

1.Definition: Sandblasting & Shot Blasting 

Sandblasting uses compressed air as a power to spray sand at a diameter of 40 to 120 mesh or pellet of 0.1 to 2.0 to the surface of the workpiece to achieve required surface treatment. The size of the pellets is different and the treatment effect is different.

Shot blasting uses a high-speed rotating impeller and the centrifugal force to throw the ball with a diameter of 0.2~3.0 (casting pill, cutting pill, stainless steel pill, etc.) to the surface of the workpiece, so that the surface reaches a certain roughness. As well as make the workpiece beautiful, or change welding tensile stress and improve its the service life

2. Blasting Media: Sand & Steel Ball

Sandblasting use hard and durable abrasives, refers to angular sand, such as corundum, emery and so on, Shot blasting use metal particular in special texture and shape (commonly called steel shot),  looks like a meatball after a period of use. 

3. Surface Treatment Purpose: Cleaning & Hardening

The main purpose of sandblasting is removing rust, oxide scales and surface preparation before coating, while shot blasting has more functions, except surface cleaning, it also increases the surface toughness, reduces deformation of heat treatment parts and improvse wear-resistance and pressure capacity, etc.

4. Spraying & Throwing

Sandblasting acts a spraying motion,  with compressed air as the power to spray the sand or pellets onto the surface to achieve a cleaner suface, or make some decoration, such as matt finishing.

Shot blasting acts a throwing method,  a centrifugal force generated when the pellet is rotated at a high speed, impacting the surface of the material to achieve removal and surface hardenning.

5. Blasting Operation 

Sand blasting machine is mainly manually operated, while shot blasting machine is mostly automatic and semi-automatic operated.