Specifying Needle Roller Bearing — ISO / DIN (Series 134) in Grade 12.9 Steel pairs the dimensional form of Needle Roller Bearing — ISO / DIN (Series 134) (ISO / DIN) with the engineering properties of Grade 12.9 Steel. This page explains when to choose the grade, how it behaves in service, and which grades to compare it against.
Why Choose Grade 12.9 Steel for Needle Roller Bearing — ISO / DIN (Series 134)
The highest common strength class, for high-load machine assembly. For needle roller bearing — iso / din (series 134), 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 |
Galvanic & Galling Considerations
For needle roller bearing — iso / din (series 134) 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.
Comparable Grades
For Needle Roller Bearing — ISO / DIN (Series 134), class 8.8 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Needle Roller Bearing — ISO / DIN (Series 134) Available in Grade 12.9 Steel
| Bore d (mm) | Outer diameter D (mm) | Width B (mm) | Dynamic load C (kN) | Reference standard |
|---|---|---|---|---|
| 8 | 15 | 12 | 7.2 | ISO 1206 / GB/T 309 |
| 10 | 17 | 12 | 8.3 | ISO 1206 / GB/T 309 |
| 12 | 19 | 12 | 9.65 | ISO 1206 / GB/T 309 |
| 15 | 23 | 12 | 12.5 | ISO 1206 / GB/T 309 |
| 20 | 28 | 16 | 18.7 | ISO 1206 / GB/T 309 |
| 25 | 33 | 16 | 22.8 | ISO 1206 / GB/T 309 |
| 30 | 40 | 20 | 33.0 | ISO 1206 / GB/T 309 |
| 40 | 50 | 20 | 42.5 | ISO 1206 / GB/T 309 |