For thrust bearing in Grade 12.9 Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for Grade 12.9 Steel (class 12.9) is summarized below together with every size supplied.
Why Choose Grade 12.9 Steel for Thrust Bearing — ISO / DIN (Series 126)
The highest common strength class, for high-load machine assembly. For thrust bearing — iso / din (series 126), 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 thrust bearing — iso / din (series 126) 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 thrust bearing — iso / din (series 126) 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 Thrust Bearing — ISO / DIN (Series 126) Available in Grade 12.9 Steel
| Bore d (mm) | Outer diameter D (mm) | Total height H (mm) | Dynamic axial load Ca (kN) | Limit speed (rpm) | Reference standard |
|---|---|---|---|---|---|
| 10 | 24 | 9 | 9.65 | 4000 | ISO 104 / GB/T 301 |
| 15 | 28 | 9 | 11.5 | 3800 | ISO 104 / GB/T 301 |
| 20 | 35 | 10 | 17.0 | 3200 | ISO 104 / GB/T 301 |
| 25 | 42 | 11 | 22.0 | 2800 | ISO 104 / GB/T 301 |
| 30 | 47 | 11 | 27.0 | 2400 | ISO 104 / GB/T 301 |
| 40 | 60 | 13 | 42.5 | 2000 | ISO 104 / GB/T 301 |
| 50 | 70 | 14 | 52.0 | 1700 | ISO 104 / GB/T 301 |
| 60 | 85 | 17 | 70.0 | 1500 | ISO 104 / GB/T 301 |
| 80 | 105 | 19 | 93.0 | 1200 | ISO 104 / GB/T 301 |