Specifying Deep Groove Ball Bearing — ISO / DIN (Series 129) in Grade 8.8 Steel pairs the dimensional form of Deep Groove Ball Bearing — ISO / DIN (Series 129) (ISO / DIN) with the engineering properties of Grade 8.8 Steel. This page explains when to choose the grade, how it behaves in service, and which grades to compare it against.
Why Choose Grade 8.8 Steel for Deep Groove Ball Bearing — ISO / DIN (Series 129)
The workhorse medium-carbon alloy grade for structural joints. For deep groove ball bearing — iso / din (series 129), this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
Corrosion Behavior in Service
Carbon and alloy steel deep groove ball bearing — iso / din (series 129) 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 deep groove ball bearing — iso / din (series 129) 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 Deep Groove Ball Bearing — ISO / DIN (Series 129) Available in Grade 8.8 Steel
| Bore d (mm) | Outer diameter D (mm) | Width B (mm) | Dynamic load C (kN) | Limit speed (rpm) | Reference standard |
|---|---|---|---|---|---|
| 10 | 30 | 9 | 5.1 | 32000 | ISO 15 / GB/T 276 |
| 12 | 32 | 10 | 6.95 | 28000 | ISO 15 / GB/T 276 |
| 15 | 35 | 11 | 7.65 | 24000 | ISO 15 / GB/T 276 |
| 17 | 40 | 12 | 9.56 | 22000 | ISO 15 / GB/T 276 |
| 20 | 47 | 14 | 12.7 | 18000 | ISO 15 / GB/T 276 |
| 25 | 52 | 15 | 14.0 | 16000 | ISO 15 / GB/T 276 |
| 30 | 62 | 16 | 19.5 | 13000 | ISO 15 / GB/T 276 |
| 35 | 72 | 17 | 25.5 | 11000 | ISO 15 / GB/T 276 |
| 40 | 80 | 18 | 30.7 | 10000 | ISO 15 / GB/T 276 |
| 45 | 85 | 19 | 33.2 | 9500 | ISO 15 / GB/T 276 |
| 50 | 90 | 20 | 35.1 | 9000 | ISO 15 / GB/T 276 |
| 60 | 110 | 22 | 52.7 | 7500 | ISO 15 / GB/T 276 |