| Grade | Variation of ball diameter VDws(≤) (μm) | Deviation from spherical form ∆RSw(≤) (μm) | Surface roughness Ra(≤) (μm) | Variation of ball lot diameter VDwL(≤) (μm) | Ball gauge interval (μm) | Preferred ball gauges (μm) |
| G 3 | 0.08 | 0.08 | 0.01 | 0.13 | 0.5 | -5 ~ +5 |
| G 5 | 0.13 | 0.13 | 0.014 | 0.25 | 1 | -5 ~ +5 |
| G 10 | 0.25 | 0.25 | 0.02 | 0.5 | 1 | -9 ~ +9 |
| G 16 | 0.4 | 0.4 | 0.025 | 0.8 | 2 | -10 ~ +10 |
| G 20 | 0.5 | 0.5 | 0.032 | 1 | 2 | -10 ~ +10 |
| G 24 | 0.6 | 0.6 | 0.04 | 1.2 | 2 | -12 ~ +12 |
| G 28 | 0.7 | 0.7 | 0.05 | 1.4 | 2 | -12 ~ +12 |
| G 40 | 1 | 1 | 0.06 | 2 | 4 | -16 ~ +16 |
| G 60 | 1.5 | 1.5 | 0.08 | 3 | 6 | -18 ~ +18 |
| G 100 | 2.5 | 2.5 | 0.1 | 5 | 10 | -40 ~ +40 |
| G 200 | 5 | 5 | 0.15 | 10 | 15 | -60 ~ +60 |
| Grade | Variation of ball diameter VDws(≤) (μm) | Deviation from spherical form ∆RSw(≤) (μm) | Surface roughness Ra(≤) (μm) | Variation of ball lot diameter VDwL(≤) (μm) | Nominal ball diameter tolerance (μm) |
| G3A | 0.08 | 0.08 | 0.012 | 0.13 | * |
| G5A | 0.13 | 0.13 | 0.020 | 0.25 | * |
| G10A | 0.25 | 0.25 | 0.025 | 0.5 | * |
| G16A | 0.4 | 0.4 | 0.025 | 0.8 | * |
| G24A | 0.6 | 0.6 | 0.05 | 1.2 | * |
| G48A | 1.2 | 1.2 | 0.08 | 2.4 | * |
| G100A | 2.5 | 2.5 | 0.125 | 5 | ±12.5 |
| G200A | 5 | 5 | 0.2 | 10 | ±25 |
| G500A | 13 | 13 | * | 25 | ±50 |
| G1000A | 25 | 25 | * | 50 | ±125 |
| G2000A | 50 | 50 | * | 100 | ±250 |
| Grade | Nominal Size (mm) | Limit Deviations (μm) | Variation of ball diameter VDws(≤) (μm) | Deviation from spherical form ∆RSw(≤) (μm) | Surface roughness Ra(≤) (μm) | Variation of ball lot diameter VDwL(≤) (μm) | Ball gauge interval (μm) | Preferred ball gauges (μm) |
| G 3 | 0 ~ 12.7 | ± 5.32 | 0.08 | 0.08 | 0.01 | 0.13 | 0.5 | -5 ~ +5 |
| G 5 | 0 ~ 12.7 | ± 5.63 | 0.13 | 0.13 | 0.014 | 0.25 | 1 | -5 ~ +5 |
| G 10 | 0 ~ 25.4 | ± 9.75 | 0.25 | 0.25 | 0.02 | 0.5 | 1 | -9 ~ +9 |
| G 16 | 0 ~ 25.4 | ± 11.4 | 0.4 | 0.4 | 0.025 | 0.8 | 2 | -10 ~ +10 |
| G 20 | 0 ~ 38.1 | ± 11.5 | 0.5 | 0.5 | 0.032 | 1 | 2 | -10 ~ +10 |
| G 28 | 0 ~ 50.8 | ± 13.7 | 0.7 | 0.7 | 0.05 | 1.4 | 2 | -12 ~ +12 |
| G 40 | 0 ~ 100 | ± 19 | 1 | 1 | 0.06 | 2 | 4 | -16 ~ +16 |
| G 80 | 0 ~ 100 | ± 14 | 2 | 2 | 0.1 | * | 4 | -12 ~ +12 |
| G 100 | 0 ~ 150 | ± 47.5 | 2.5 | 2.5 | 0.1 | 5 | 10 | -40 ~ +40 |
| G 200 | 0 ~ 150 | ± 72.5 | 5 | 5 | 0.15 | 10 | 10 | -60 ~ +60 |
| G 300 | 0 ~ 25.4 | ± 70 | 10 | 10 | 0.2 | * | 20 | -60 ~ +60 |
| G 300 | 25.4 ~ 50.8 | ± 105 | 15 | 15 | 0.2 | * | 30 | -90 ~ +90 |
| G 300 | 50.8 ~ 75 | ± 140 | 20 | 20 | 0.2 | * | 40 | -120 ~ +120 |
| G 500 | 0 ~ 25.4 | ± 75 | 25 | 25 | * | * | 50 | -50 ~ +50 |
| G 500 | 25.4 ~ 50.8 | ± 112.5 | 25 | 25 | * | * | 75 | -75 ~ +75 |
| G 500 | 50.8 ~ 75 | ± 150 | 25 | 25 | * | * | 100 | -100 ~ +100 |
| G 500 | 75 ~ 100 | ± 187.5 | 32 | 32 | * | * | 125 | -125 ~ +125 |
| G 500 | 100 ~ 125 | ± 225 | 38 | 38 | * | * | 150 | -150 ~ +150 |
| G 500 | 125 ~ 150 | ± 262.5 | 44 | 44 | * | * | 175 | -175 ~ +175 |
| G 600 | all | ± 200 | * | * | * | * | * | * |
| G 700 | all | ± 1000 | * | * | * | * | * | * |
| Grade | Variation of ball diameter VDws(≤) (μm) | Deviation from spherical form ∆RSw(≤) (μm) | Surface roughness Ra(≤) (μm) | Variation of ball lot diameter VDwL(≤) (μm) | Ball gauge interval (μm) | Preferred ball gauges (μm) |
| G 3 | 0.08 | 0.08 | * | 0.13 | 0.5 | -5 ~ +5 |
| G 5 | 0.13 | 0.13 | 0.02 | 0.25 | 1 | -5 ~ +5 |
| G 10 | 0.25 | 0.25 | 0.02 | 0.5 | 1 | -9 ~ +9 |
| G 16 | 0.4 | 0.4 | 0.032 | 0.8 | 2 | -10 ~ +10 |
| G 20 | 0.5 | 0.5 | 0.04 | 1 | 2 | -10 ~ +10 |
| G 24 | 0.6 | 0.6 | 0.04 | 1.2 | 2 | -12 ~ +12 |
| G 28 | 0.7 | 0.7 | 0.05 | 1.4 | 2 | -12 ~ +12 |
| G 40 | 1 | 1 | 0.08 | 2 | 4 | -16 ~ +16 |
| G 60 | 1.5 | 1.5 | 0.1 | 3 | 6 | -18 ~ +18 |
| G 100 | 2.5 | 2.5 | 0.125 | 5 | 10 | -40 ~ +40 |
| G 200 | 5 | 5 | 0.2 | 10 | 15 | -60 ~ +60 |
Notes: Precision grades of Japanese steel ball standard JIB 1501-2009 Rolling Bearings – Balls and Korean steel ball standard KS B 2001:2001 bearing steel balls are totally same as the precision grade of ISO 3290-1:2008 Rolling bearings — Balls – Part 1: Steel balls. Here do not list independently.