This SAE recommended practice provides some procedure for determining shot peening coverage and relating coverage to part exposure to the media stream. Effectiveness of shot peening is directly dependent on coverage. Either incomplete or excessive coverage can be detrimental to fatigue strength and life.
Rationale:
The document is being revised to: (1) establish guidelines for visual (magnified) examination to determine coverage. Alternative indirect methods can assist but not necessarily replace visual examination. Revision (2) clarifies that full/coverage allows random unpeened islands smaller than the peening dimples.