Stainless steel balls
Product Feature
Corrosion-resistant steel balls are mainly used for valves, which are used in a corrosive environment. We offer two types of stainless steel balls; martensitic (SUS400) and austenitic (SUS300). In particular, steel balls made of SUS440 have strength and accuracy comparable to those from SUJ2, as well as excellent corrosion resistance, so they are also used for bearings which require corrosion resistance.
Mechanical Property
| Classification | Hardness(HV) | Corrosion resistance | Magnetism | Feature | |
|---|---|---|---|---|---|
| Martensitic stainless steel balls | SUS440C | 800 | ◎ | ○ | This material is the hardest stainless steel among those specified by JIS. |
| SUS420J2 | 600～700 | ◎ | ○ | This material is modified from 440C by reducing the size of coarse carbide. | |
| SUS431 | 500 | ◎◎ | ○ | This material has the highest corrosion resistance among the martensitic stainless steels specified by JIS due to addition of Ni. | |
| Austenitic stainless steel balls | SUS304 | 200 | ◎◎◎ | × | This material has excellent corrosion resistance due to the addition of Ni. |
| SUS316 | 200 | ◎◎◎◎ | × | This material has the highest corrosion resistance among the standard stainless steels offered by AKS due to addition of Ni & Mo. | |
Usage Example
- ・Bearings for corrosion-resistance environment
- ・Fuel compression pumps for automobiles
- ・Valves, high-pressure valves, etc.
Valves (courtesy of Hitachi Automotive Systems, Ltd.)
Product Specification
1.Chemical Composition of Material (%)
| C | Si | Mn | P | S | Ni | Cr | Mo | |
|---|---|---|---|---|---|---|---|---|
| ●Martensitic stainless steel balls | ||||||||
| SUS420J1 JIS | 0.16～0.25 | 1.00 or less | 1.00 or less | 0.040 or less | 0.030 or less | (1) | 12.00～14.00 | - |
| SUS420J2 JIS | 0.26～0.40 | 1.00 or less | 1.00 or less | 0.040 or less | 0.030 or less | (1) | 12.00～14.00 | - |
| SUS440C JIS | 0.95～1.20 | 1.00 or less | 1.00 or less | 0.040 or less | 0.030 or less | (1) | 16.00～18.00 | (2) |
| SUS431 JIS | 0.20 or less | 1.00 or less | 1.00 or less | 0.040 or less | 0.030 or less | 1.25～2.50 | 15.00～17.00 | - |
| ●Austenitic stainless steel balls | ||||||||
| SUS304 JIS | 0.08or less | 1.00 or less | 2.00 or less | 0.045or less | 0.030 or less | 8.00～10.50 | 18.00～20.00 | - |
| SUJ316 JIS | 0.08or less | 1.00 or less | 2.00 or less | 0.045or less | 0.030 or less | 10.00～14.00 | 16.00～18.00 | 2.00～3.00 |
- Remark
- 1）The content of Ni may be 0.60% or less.
- 2）The content of Mo may be 0.75% or less.
- * The chemical compositions of stainless steel bars and wire are the same.
2.Dimensions and dimensional accuracy
●SUS440C
According to the Japanese Industrial Standard JIS B1501-2009
●SUS420J2、SUS431、SUS304、SUS316
| Classification of ball materials | Ball sizes |
|---|---|
| Martensitic stainless steel balls | 1/8（3.175mm）～ 1 1/2（38.100mm） |
| Austenitic stainless steel balls | 1/8（3.175mm）～2（50.800mm） |
※Balls of sizes or grades other than the above-mentioned can be manufactured at your request.
| Range of ball sizes | Gauges | Variation of ball lot diameter（Max） | Deviation from spherical form（Max） |
|---|---|---|---|
| 1/8（3.175mm）～1/2（12.700mm） | ±15 | 2 | 2 |
| 9/16（14.288mm）～2（50.800mm） | 3 | 3 |
3.Hardness
●SUS440C ⇒59～66 HRC