Grade 8.8 Steel Fender Washers combine the dimensional form of DIN 9021 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 Fender Washers
The workhorse medium-carbon alloy grade for structural joints. For fender washers, 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 fender washers 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 Fender Washers, 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 Fender Washers Available in Grade 8.8 Steel
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Thickness h (mm) | Reference standard | Notes |
|---|---|---|---|---|---|
| M3 | 3.2 | 9.0 | 0.8 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M4 | 4.3 | 12.0 | 1.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M5 | 5.3 | 15.0 | 1.2 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M6 | 6.4 | 18.0 | 1.6 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M8 | 8.4 | 24.0 | 2.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M10 | 10.5 | 30.0 | 2.5 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M12 | 13.0 | 37.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M14 | 15.0 | 44.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M16 | 17.0 | 50.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M20 | 21.0 | 60.0 | 4.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M24 | 25.0 | 72.0 | 5.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M30 | 31.0 | 90.0 | 6.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M36 | 37.0 | 110.0 | 8.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |