Balls for rolling bearings
Product Features
Steel balls are mainly used for bearings. They support the rotating parts of all types of machines, such as automobiles. The common material is SUJ2 (*), and there are more than 100 production sizes available. S teel balls are our main products.
*What is SUJ2?
SUJ2 is a high-carbon chromium bearing steel in conformity with JIS G 4805. Non-metal inclusions, which have a harmful effect on the durability of steel, are minimized by the vacuum degassing method.
Mechanical Property(Reference)
| Physical properties | Density (g/cm³) | Hardness （HV） | Young's modulus （GPa） | Poisson's ratio | Coefficient of thermal expnsion （×10-6/℃） | Thermal conductivity （W/mK） | Magnetism | Conductivity |
|---|---|---|---|---|---|---|---|---|
| SUJ2 | 7.8 | 850 | 207 | 0.30 | 12.5 | 46 | ○ | ○ |
Usage Example
- ・Ball bearings (Cars, home appliances, industrial machines, etc.)
- Components of cars: Motor, generator, hub, constant-velocity joint (CVJ), steering, electromagnetic clutch, wiper, transmission, etc.
- ・Linear guides
- ・Ball screws and more
Hub (courtesy of NSK Ltd.)
Product Specification
1.Chemical Composition of Material (%)
| C | Si | Mn | P | S | Cr | |
|---|---|---|---|---|---|---|
| SUJ2(JIS) | 0.95～1.10 | 0.15～0.35 | 0.50 or less | 0.025 or less | 0.025 or less | 1.30～1.60 |
- Remarks:
- 1）The content of Mo as an impurity shall not exceed 0.08%. Those of Ni and Cu shall not exceed 0.25%, respectively. Note that the content of Cu in a wire rod shall be 0.20% or less.
- 2）The elements that are not listed in the table can be added with a content of 0.25% or less.
- 3）Our products are mainly made of SUJ2.
2.Dimensions and dimensional accuracy
According to the Japanese Industrial Standard JIS B1501-2009
3.Hardness
| Ball size | Hardness | |
|---|---|---|
| HV | HRC | |
| 0.3～3mm | 772～900 | （63～67） |
| 1/8～30mm | - | 62～67 |
| 1 3/16～4 1/8 | - | 61～67 |