Shot blasting is a specialized surface finishing process where small metal (or mineral) pellets, called blast media, are thrown onto the surface of a work piece at incredibly high speeds, ranging from 200-800 feet per second. The impact on the work pieces from this process is what produces the desired surface finishing effect.
Shot blasting can help achieve surface cleaning, surface preparation, descaling, deburring, deflashing, and shot peening.
The process components of a shot blasting system include a shot blast machine, raw and finished work pieces, blast media, dust, and other byproducts.
Turbine blast machines are the most powerful machines on the market. They are ideal for high volumes of mass produced bulk parts or for blasting large, heavy parts. The technical principle is based around the use of blasting turbines which is a rotating wheel equipped with throwing blades that pick up and throw the blast media at speeds up to 350 feet per second onto the work peice. See the video below for an animated depiction of the process:
Examples of turbine blasting equipment include:
- Spinner Hanger
- Preservation Line
- Continuous Belt
- Roller Conveyor
- Wire Mesh Belt
- Tumble Belt
- Wet Blast
Air blasting leverages the use of compressed air to accelerate the blasting media through nozzles and onto the work piece. Air blasting is highly versatile and can provide very gentle or highly aggressive shot blasting. Check out our air blast archive for more information.
A highly specialized type of air blasting worth noting is wet blasting. (link) In this process the blast media is mixed with water to create a blast “slurry” which is then fed through the nozzle using compressed air. Wet blasting is unique in that it virtually eliminates dust and provide a beautiful matte finish. It is ideal for sensitive, delicate parts.
Types of work pieces
Shot blasting can be used to finish a huge variety of parts, from small parts weighing only a fraction of an ounce to large parts weighing up to 500,000 pounds. Metal is the most common type of work piece, however, shot blasting can also be used on work pieces made out of stone, plastic, or even wood.
There are too many work pieces to list, but common applications include structural steel, aerospace and automotive components, orthopedic implants, gears, pump housings, valve bodies, castings, screws, rivets, and more.
When blasting comes to mind, many people still think of sand blasting, however, sand has been replaced with a wide variety of metal and mineral blast medias. Here are the four most common types:
- Metallic media – Carbon steel, stainless steel, aluminum, zinc.
- Mineral based media – Aluminum oxide, silicon carbide, glass beads, ceramic beads and garnet.
- Plastic media – Polyamide, duroplast, acrylic, melamine, urea, nylon.
- Organic media – Corn cob, walnut shells.
Check out our blast media archive for more information.
Post written by
Rosler Metal Finishing, USA
Technical Sales Specialist – Shot Blasting