Properly selected abrasive material plays a decisive role in the achievement of necessary quality of surface treatment.
Shot quality for shot blasting is evaluated in accordance with three criteria: price, cleaning quality and expense of metal abrasives.
Steel shot and grit are the best metal abrasives to use them in shot blasting and shot peening machines. Cast-iron abrasives have shown their total inefficiency in comparison with steel ones long ago. Despite the fact that cast-iron abrasives are chipper than steel abrasives, the cost of surface treatment with their using is very high. It is proved cast-iron abrasives expense is 3,5 times greater than steel shot and grit.
The use of steel shot ensures less wear of tools, cuts time treatment for achieving necessary quality. Also it dirties work pieces less and significantly reduces consumption of shot.
High carbon shot has special thermal treatment and possesses high durability as well as long life time.
According to the Ervin Test Machine cast-iron shot durability is from 300 to 400 passes.
The durability of steel shot according to the Ervin Test Machine is 2850-3200 passes.
Nowadays the tendency of use expanding of steel shot is definitely established.