The following are four standard descriptions of rust removal levels for shot blasting machines, using a more concise description:
Sa1: Light Shot Blasting/Shot Blasting
Surface Condition: No visible grease, dirt, loose scale, rust, or paint residue.
Characteristics: Basic cleaning only, with some deposits retained.
Sa2: Thorough Shot Blasting/Shot Blasting
Surface Condition: No grease, dirt, scale, rust, or paint residue. Scale and rust are essentially removed, with any remaining deposits firmly attached.
Process Markings: Evenly distributed shot blasting indentations.
Performance Index: Anti-slip coefficient 0.35–0.45.
Sa2.5: Very Thorough Shot Blasting/Shot Blasting
Surface Condition: No grease, dirt, scale, rust, or paint residue. Remaining deposits are limited to minor spotting or streaking.
Process Markings: Evenly distributed shot blasting indentations.
Performance Index: Anti-slip coefficient 0.45–0.5. Sa3 Clean Blasting/Shot Blasting
Surface Condition: Completely free of grease, dirt, scale, rust, or paint, exhibiting a uniform metallic luster.
Standard: Achieves the highest level of cleanliness, suitable for harsh environments.