Specifying Wedge / Taper Washer — GB/T 852 (Series 084) in Grade 8.8 Steel pairs the dimensional form of Wedge / Taper Washer — GB/T 852 (Series 084) (GB/T 852) 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 Wedge / Taper Washer — GB/T 852 (Series 084)
The workhorse medium-carbon alloy grade for structural joints. For wedge / taper washer — gb/t 852 (series 084), 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 wedge / taper washer — gb/t 852 (series 084) 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 wedge / taper washer — gb/t 852 (series 084) 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 Wedge / Taper Washer — GB/T 852 (Series 084) Available in Grade 8.8 Steel
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Mean thickness t (mm) | Slope | Reference standard |
|---|---|---|---|---|---|
| M3 | 3.5 | 6 | 1.2 | 1:6 | DIN 6917 / GB/T 853 |
| M4 | 4.5 | 8 | 1.6 | 1:6 | DIN 6917 / GB/T 853 |
| M5 | 5.5 | 11 | 2.0 | 1:6 | DIN 6917 / GB/T 853 |
| M6 | 6.5 | 13 | 2.4 | 1:6 | DIN 6917 / GB/T 853 |
| M8 | 8.5 | 17 | 3.2 | 1:6 | DIN 6917 / GB/T 853 |
| M10 | 10.5 | 22 | 4.0 | 1:6 | DIN 6917 / GB/T 853 |
| M12 | 12.5 | 26 | 4.8 | 1:6 | DIN 6917 / GB/T 853 |
| M14 | 14.5 | 30 | 5.6 | 1:6 | DIN 6917 / GB/T 853 |
| M16 | 16.5 | 35 | 6.4 | 1:6 | DIN 6917 / GB/T 853 |
| M18 | 18.5 | 39 | 7.2 | 1:6 | DIN 6917 / GB/T 853 |