In a semi-precision grade bearing, 304 and 630 stainless steel can be chosen for improved corrosion resistance over 440C. SS304 is not heat treated so load and speed capacity is significantly less than HT 52100 & 440C. It can be used for both rings and balls or SS rings with ceramic balls. SS304 & 630 stainless steel offers excellent corrosion resistance to water and excellent to good resistance when exposed to certain common acids. SS304 can be an excellent choice for food grade applications. Other applications may include marine and vacuum processes. 300 series stainless steel is also a common material used for ribbon and crown type retainers. 300 series stainless steels are generally considered non-magnetic. As SS304 & SS630 bearings are not as common as 440C, size availability and minimum order requirements apply.
| AISI 304 | AISI 440C | SAE 52100 | ||
|---|---|---|---|---|
| Specific Gravity | - | 7.93 | 7.8 | 7.8 |
| Tensile Strength | N/mm2 | 520~600 | 1900~2000 | 1680 |
| Elongation | % | 45~60 | - | - |
| Elastic Modulus | N/mm2 | 193000 | 203000 | 212000 |
| Hardness | HV HRC | 170 3.0 | 700 60.1 | 740 61.8 |
| Magnetism | - | Non Magnetic * 1 | Magnetic | Magnetic |