Grade 8.8 Steel Lifting Eye Bolt — GB/T 825 / DIN 580 (Series 037) pairs the standard GB/T 825 / DIN 580 with a Grade 8.8 Steel base material. The sections below cover why engineers select this grade for lifting eye bolt — gb/t 825 / din 580 (series 037), its corrosion and temperature behavior, and the sizes available.
Why Choose Grade 8.8 Steel for Lifting Eye Bolt — GB/T 825 / DIN 580 (Series 037)
The workhorse medium-carbon alloy grade for structural joints. For lifting eye bolt — gb/t 825 / din 580 (series 037), 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 lifting eye bolt — gb/t 825 / din 580 (series 037) 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 lifting eye bolt — gb/t 825 / din 580 (series 037) 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 Lifting Eye Bolt — GB/T 825 / DIN 580 (Series 037) Available in Grade 8.8 Steel
| Size | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Hex socket s (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 20 | 5.5 | 3 | 2.5 | ISO 4762 / GB/T 70.1 |
| M4 | 0.7 | 25 | 7.0 | 4 | 3.0 | ISO 4762 / GB/T 70.1 |
| M5 | 0.8 | 30 | 8.5 | 5 | 4.0 | ISO 4762 / GB/T 70.1 |
| M6 | 1.0 | 40 | 10.0 | 6 | 5.0 | ISO 4762 / GB/T 70.1 |
| M8 | 1.25 | 50 | 13.0 | 8 | 6.0 | ISO 4762 / GB/T 70.1 |
| M10 | 1.5 | 60 | 16.0 | 10 | 8.0 | ISO 4762 / GB/T 70.1 |
| M12 | 1.75 | 80 | 18.0 | 12 | 10.0 | ISO 4762 / GB/T 70.1 |
| M14 | 2.0 | 80 | 21.0 | 14 | 12.0 | ISO 4762 / GB/T 70.1 |
| M16 | 2.0 | 100 | 24.0 | 16 | 14.0 | ISO 4762 / GB/T 70.1 |
| M18 | 2.5 | 100 | 27.0 | 18 | 14.0 | ISO 4762 / GB/T 70.1 |
| M20 | 2.5 | 120 | 30.0 | 20 | 17.0 | ISO 4762 / GB/T 70.1 |
| M24 | 3.0 | 150 | 36.0 | 24 | 19.0 | ISO 4762 / GB/T 70.1 |
| M30 | 3.5 | 180 | 45.0 | 30 | 22.0 | ISO 4762 / GB/T 70.1 |
| M36 | 4.0 | 200 | 54.0 | 36 | 27.0 | ISO 4762 / GB/T 70.1 |