Grade 8.8 Steel Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054) pairs the standard GB/T 6181 / ISO 4035 with a Grade 8.8 Steel base material. The sections below cover why engineers select this grade for hex slotted nut — gb/t 6181 / iso 4035 (series 054), its corrosion and temperature behavior, and the sizes available.
Why Choose Grade 8.8 Steel for Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054)
The workhorse medium-carbon alloy grade for structural joints. For hex slotted nut — gb/t 6181 / iso 4035 (series 054), 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 hex slotted nut — gb/t 6181 / iso 4035 (series 054) 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 hex slotted nut — gb/t 6181 / iso 4035 (series 054) 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 Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054) Available in Grade 8.8 Steel
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 0.5 | 5.5 | 6.01 | 1.8 | ISO 4035 / GB/T 6172 |
| M4 | 0.7 | 7.0 | 7.66 | 2.2 | ISO 4035 / GB/T 6172 |
| M5 | 0.8 | 8.0 | 8.79 | 2.7 | ISO 4035 / GB/T 6172 |
| M6 | 1.0 | 10.0 | 11.05 | 3.2 | ISO 4035 / GB/T 6172 |
| M8 | 1.25 | 13.0 | 14.38 | 4.0 | ISO 4035 / GB/T 6172 |
| M10 | 1.5 | 16.0 | 17.77 | 5.0 | ISO 4035 / GB/T 6172 |
| M12 | 1.75 | 18.0 | 20.03 | 6.0 | ISO 4035 / GB/T 6172 |
| M14 | 2.0 | 21.0 | 23.36 | 7.0 | ISO 4035 / GB/T 6172 |
| M16 | 2.0 | 24.0 | 26.75 | 8.0 | ISO 4035 / GB/T 6172 |
| M18 | 2.5 | 27.0 | 30.14 | 9.0 | ISO 4035 / GB/T 6172 |
| M20 | 2.5 | 30.0 | 33.53 | 10.0 | ISO 4035 / GB/T 6172 |
| M24 | 3.0 | 36.0 | 39.98 | 12.0 | ISO 4035 / GB/T 6172 |
| M30 | 3.5 | 46.0 | 50.85 | 15.0 | ISO 4035 / GB/T 6172 |
| M36 | 4.0 | 55.0 | 60.79 | 18.0 | ISO 4035 / GB/T 6172 |