Maintain Consistent Surface Finish on Delicate Castings

Business Challenge

Transmet Cast Shot is relatively soft compared to many other blast materials. The shot is cast in air, resulting in a teardrop shape that flies in the face on conventional shot peening norms. Additionally, metallic shot will either work-harden or work-soften as it becomes a working mix.

Occasionally Transmet encounters situations where blasting with brand new shot results in a different surface profile than blasting with a conditioned working mix of shot.

Transmet Approach

The initial teardrop shape typically lasts 50 to 100 cycles before the tail is pounded into the shot, making it round. This makes it easy to determine visually when shot is conditioned into a working mix.

Rounding the shot was determined to provide the most consistent surface finish on delicate castings. The high durability of Transmet Cast Shot results in small, periodic additions to the machine to maintain full amperage on the blast wheel.

Project Outcome

Making small, periodic additions to the blast machine ensures more than 90% of the shot will be conditioned, while less than 10% of the working mix will be brand new shot. Quality results are repeatable day after day.

Many of Transmet’s customers have determined the daily additions needed in order to keep amp load on the wheel consistent and place them on specific intervals (such as the beginning of each shift).

The pictures move left to right from cast shot, to 500 cycles, to working mix: