A4 Stainless Steel Angular Contact Ball Bearing — ISO / DIN (Series 138) pairs the standard ISO / DIN with a A4 Stainless Steel base material. The sections below cover why engineers select this grade for angular contact ball bearing — iso / din (series 138), its corrosion and temperature behavior, and the sizes available.
Why Choose A4 Stainless Steel for Angular Contact Ball Bearing — ISO / DIN (Series 138)
Specified for marine, coastal and chemical applications. For angular contact ball bearing — iso / din (series 138), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Angular Contact Ball Bearing — ISO / DIN (Series 138) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless angular contact ball bearing — iso / din (series 138): (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Sizes of Angular Contact Ball Bearing — ISO / DIN (Series 138) Available in A4 Stainless Steel
| Bore d (mm) | Outer diameter D (mm) | Width B (mm) | Contact angle (deg) | Dynamic load C (kN) | Reference standard |
|---|---|---|---|---|---|
| 10 | 30 | 9 | 15 | 5.85 | ISO 76 / GB/T 292 |
| 15 | 35 | 11 | 15 | 8.06 | ISO 76 / GB/T 292 |
| 20 | 47 | 14 | 15 | 12.5 | ISO 76 / GB/T 292 |
| 25 | 52 | 15 | 15 | 14.8 | ISO 76 / GB/T 292 |
| 30 | 62 | 16 | 15 | 20.3 | ISO 76 / GB/T 292 |
| 40 | 80 | 18 | 15 | 32.5 | ISO 76 / GB/T 292 |
| 50 | 90 | 20 | 15 | 37.5 | ISO 76 / GB/T 292 |
| 60 | 110 | 22 | 25 | 55.0 | ISO 76 / GB/T 292 |
| 70 | 125 | 24 | 25 | 70.2 | ISO 76 / GB/T 292 |
| 80 | 140 | 26 | 25 | 82.4 | ISO 76 / GB/T 292 |