Bearing Steel Ball Grade
Steel ball grade classification:
The grades of steel balls are generally divided according to parameters such as diameter, roundness, and surface finish. Common grades include G3, G5, G10, G16, G20, G24, G28, G40, G60, G100, G200, etc.
Accuracy index:
- TDB: Diameter tolerance range: specifies the maximum and minimum deviation values allowed for the steel ball diameter.
- VDWL: Ball batch diameter variation: When a batch of steel balls is used together, this indicator measyres the consistency of the diameter of the entire batch of steel balls.
- VDWS: Ball diameter variation: This is an indicator to measyre the consistency of steel ball diameter, which is crucial to ensure the stability and accuracy of the rolling element.
- △Spn: Spherical error: refers to the degree of deviation of the steel ball from the perfect spherical shape, reflecting the roundness of the steel ball.
- Ra: Surface roughness: describes the smoothness of the steel ball surface, which is important for reducing friction and increasing service life.
Precision standard unit: These precision indicators are usually measyred in microns (μm) to ensure precise control of rolling element performance.
Customization service: Autoround can customize G10 and above bearing steel balls according to customer needs to meet the high precision requirements of special applications.
| ISO 3290 2001 | ||||||
| Level | Ball diameter | TDB | VDWL | VDWS | △Spn | Ra |
| G3 | 1/16″～40mm
|
±5 | 0.13 | 0.08 | 0.08 | 0.01 |
| G5 | ±5 | 0.25 | 0.13 | 0.13 | 0.014 | |
| G10 | ±9 | 0.5 | 0.25 | 0.25 | 0.02 | |
| G16 | ±10 | 0.8 | 0.4 | 0.4 | 0.025 | |
| G20 | ±10 | 1 | 0.5 | 0.5 | 0.032 | |
| G24 | ±12 | 1.2 | 0.6 | 0.6 | 0.04 | |
| G28 | ±12 | 1.4 | 0.7 | 0.7 | 0.05 | |
| G40 | ±16 | 2 | 1 | 1 | 0.06 | |
| G60 | ±18 | 3 | 1.5 | 1.5 | 0.08 | |
| G100 | ±40 | 5 | 2.5 | 2.5 | 0.1 | |
| G200 | ±60 | 10 | 5 | 5 | 0.15 | |
| American AFBMA 10 1989 | ||||||
| Level | Ball diameter | TDB | VDWL | VDWS | △Spn | Ra |
| G3 | 1/16″～40mm
|
±0.76 | 0.13 | 0.08 | 0.08 | 0.012 |
| G5 | ±1.27 | 0.25 | 0.13 | 0.13 | 0.02 | |
| G10 | ±2.54 | 0.5 | 0.25 | 0.25 | 0.025 | |
| G16 | ±2.54 | 0.8 | 0.4 | 0.4 | 0.032 | |
| G24 | ±2.54 | 1.2 | 0.6 | 0.6 | 0.05 | |
| G48 | ±5.08 | 2.4 | 1.2 | 1.2 | 0.08 | |
| G100 | ±12.7 | 5 | 2.5 | 2.5 | 0.125 | |
| G200 | ±25.4 | 10 | 5 | 5 | 0.2 | |
| G500 | ±50.8 | 25 | 13 | 13 | …… | |
| G1000 | ±127 | 50 | 25 | 25 | …… | |
| G2000 | ±127 | 100 | 50 | 50 | …… | |
| Japan JIS B 1501 198 | ||||||
| Level | Ball diameter | TDB | VDWL | VDWS | △Spn | Ra |
| G3 | 1/16″～40mm
|
±5 | 0.13 | 0.08 | 0.08 | 0.012 |
| G5 | ±5 | 0.25 | 0.13 | 0.13 | 0.02 | |
| G10 | ±9 | 0.5 | 0.25 | 0.25 | 0.025 | |
| G16 | ±10 | 0.8 | 0.4 | 0.4 | 0.032 | |
| G20 | ±10 | 1 | 0.5 | 0.5 | 0.04 | |
| G28 | ±12 | 1.4 | 0.7 | 0.7 | 0.05 | |
| G40 | ±16 | 2 | 1 | 1 | 0.008 | |
| G60 | ±25 | 3 | 1.5 | 1.5 | 0.095 | |
| G100 | ±40 | 5 | 2.5 | 2.5 | 0.125 | |
| G200 | ±60 | 10 | 5 | 5 | 0.2 | |
| G200 | ±60 | 10 | 5 | 5 | 0.15 | |
| German DIN 5401 2002 | ||||||
| Level | Ball diameter | TDB | VDWL | VDWS | △Spn | Ra |
| G3 | 1/16″～1/2″
|
±5.32 | 0.13 | 0.08 | 0.08 | 0.01 |
| G5 | ±5.63 | 0.25 | 0.13 | 0.13 | 0.014 | |
| G10 | 1/16″～1″
|
±9.75 | 0.5 | 0.25 | 0.25 | 0.02 |
| G16 | ±11.4 | 0.8 | 0.4 | 0.4 | 0.025 | |
| G20 | 1/16″～1 1/2″ | ±11.5 | 1 | 0.5 | 0.5 | 0.032 |
| G28 | 1/16″～40mm
|
±13.7 | 1.4 | 0.7 | 0.7 | 0.05 |
| G40 | ±19 | 2 | 1 | 1 | 0.06 | |
| G100 | ±47.5 | 5 | 2.5 | 2.5 | 0.1 | |
| G200 | ±72.5 | 10 | 5 | 5 | 0.15 | |
| G300 | 1/16″～1″ | ±70 | —- | 10 | 10 | 0.2 |
| G300 | 1″～40mm | ±+105 | —- | 15 | 15 | 0.2 |
| G500 | 1/16″～1″ | ±75 | —- | 25 | 25 | 0.2 |
| G500 | 1″～40mm | ±112.5 | —- | 25 | 25 | 0.2 |
| G600 | 1/16″～40mm | ±200 | —- | —- | —- | —- |
| G700 | ±1000 | —- | —- | —- | —- | |