Grade 8.8 Steel Housed (Pillow Block) Bearing combine the dimensional form of ISO / DIN with the material properties of grade class 8.8: requires plating (zinc) for corrosion protection, magnetic, service range up to approx. +300 °C. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose Grade 8.8 Steel for Housed (Pillow Block) Bearing — ISO / DIN (Series 121)
The workhorse medium-carbon alloy grade for structural joints. For housed (pillow block) bearing — iso / din (series 121), 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 |
Galvanic & Galling Considerations
For housed (pillow block) bearing — iso / din (series 121) 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 Housed (Pillow Block) Bearing — ISO / DIN (Series 121), class 10.9 or 12.9 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 Housed (Pillow Block) Bearing — ISO / DIN (Series 121) Available in Grade 8.8 Steel
| Shaft size (mm) | Housing length (mm) | Total height (mm) | Bolt center distance (mm) | Bolt size | Reference standard |
|---|---|---|---|---|---|
| 15 | 90 | 38 | 65 | M10 | ISO 113 / GB/T 7813 |
| 20 | 108 | 42 | 75 | M10 | ISO 113 / GB/T 7813 |
| 25 | 127 | 47 | 90 | M12 | ISO 113 / GB/T 7813 |
| 30 | 140 | 55 | 100 | M12 | ISO 113 / GB/T 7813 |
| 35 | 162 | 62 | 115 | M14 | ISO 113 / GB/T 7813 |
| 40 | 175 | 68 | 130 | M14 | ISO 113 / GB/T 7813 |
| 50 | 205 | 75 | 150 | M16 | ISO 113 / GB/T 7813 |
| 60 | 250 | 85 | 180 | M16 | ISO 113 / GB/T 7813 |
| 80 | 300 | 105 | 220 | M20 | ISO 113 / GB/T 7813 |