Grade 12.9 Steel Angular Contact Ball Bearing — ISO / DIN (Series 111) pairs the standard ISO / DIN with a Grade 12.9 Steel base material. The sections below cover why engineers select this grade for angular contact ball bearing — iso / din (series 111), its corrosion and temperature behavior, and the sizes available.
Why Choose Grade 12.9 Steel for Angular Contact Ball Bearing — ISO / DIN (Series 111)
The highest common strength class, for high-load machine assembly. For angular contact ball bearing — iso / din (series 111), this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 12.9 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating or black-oxide protection |
Corrosion Behavior in Service
Carbon and alloy steel angular contact ball bearing — iso / din (series 111) require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Galvanic & Galling Considerations
For angular contact ball bearing — iso / din (series 111) in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.
Sizes of Angular Contact Ball Bearing — ISO / DIN (Series 111) Available in Grade 12.9 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 |