The Logic Behind Selecting Hard Media

Author:  Kumar Balan | Blast Cleaning and Shot Peening Specialist
Source:  The Shot Peener magazine, Vol 39, Issue 1, Winter 2025
Doc ID:  2025003
Year of Publication:  2025
Abstract:  
INTRODUCTION The great Leonardo da Vinci, in current times, would have been considered an individual with unsure prospects due to his variable interests. He was an active painter, draughtsman, engineer, scientist, theorist, sculptor, and architect (and you thought your life was difficult because you had to re-plot a saturation curve due to media contamination). Nevertheless, one of his quotes reads, “Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.” Incapable of such profound thoughts, I am going to plagiarize his revelation into a relevant article for our discussions here! Recently, I was trying to analyze the actions of a customer that attempted to optimize their cleaning process. This customer had determined that changing shot size from S-230 to S-330 would give them better quality cleaning, reduced re-blast and other related benefits—all positively impacting productivity. This exercise did result in some process improvements but there was a price to pay with the use of a larger size media. Tight geometries on their structural steel fabrication remained uncleaned. I attributed this to the fact that due to its relatively larger size, S-330 had less particles per pound of shot than S-230. Further, the reduced percentage of small particles in their work mix might have contributed to lack of “scouring” action that was previously carried out by smaller particles of abrasive. Cause and effect were clear and obvious.


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