National Standard G Series Steel Grit Size, Particle Diameter & Application Comparison Table
| Model | Particle Size Range (mm) | Reference Ra Roughness | Main Applicable Workpieces |
|---|---|---|---|
| G12 | 2.00–2.80 | 70–100μm | Heavy rust removal for thick steel plates, sand cleaning for large castings, thick oxide scale elimination |
| G14 | 1.40–2.00 | 55–80μm | Heavy steel structures, bridges, heavy rust cleaning for ship hulls |
| G16 | 1.00–1.40 | 40–65μm | Pipelines, ordinary steel frames, conventional blasting priming for containers |
| G18 | 0.71–1.00 | 30–50μm | Mechanical castings, forklift parts, shot blasting for regular stampings |
| G20 | 0.60–0.85 | 25–40μm | Fatigue strengthening for gears, crankshafts, springs (mainstream strengthening grade) |
| G25 | 0.42–0.60 | 20–32μm | Auto spare small parts, bearing components, stress strengthening for precision forgings |
| G30 | 0.30–0.42 | 12–22μm | Matte finishing for stainless steel & aluminum parts, fine substrate before spraying |
| G40 | 0.21–0.30 | 8–15μm | Thin plates, thin-walled parts, light blasting for decorative surfaces, fine treatment prior to plating |
| G50/G80 | 0.12–0.21 | ＜10μm | Ultra-thin sheets, medical devices, fine polishing priming |
Key Selection Tips
1. High adhesion & thick paint film: Medium-coarse grit (G14–G18)
2. Anti-fatigue strengthening: Stick to G20/G25 for uniform and stable compressive stress
3. Fine appearance, thin paint/electroplating: Fine grit G30 and smaller
4. Plates thinner than 3mm: Do not use coarse grit above G16 to avoid deformation
