Grade 8.8 Steel Custom Hex Bolt (GHJ Series) — GB/T 5783 / ISO 4017 (Series 009) pairs the standard GB/T 5783 / ISO 4017 with a Grade 8.8 Steel base material. The sections below cover why engineers select this grade for custom hex bolt (ghj series) — gb/t 5783 / iso 4017 (series 009), its corrosion and temperature behavior, and the sizes available.
Why Choose Grade 8.8 Steel for Custom Hex Bolt (GHJ Series) — GB/T 5783 / ISO 4017 (Series 009)
The workhorse medium-carbon alloy grade for structural joints. For custom hex bolt (ghj series) — gb/t 5783 / iso 4017 (series 009), 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 custom hex bolt (ghj series) — gb/t 5783 / iso 4017 (series 009) 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.
Comparable Grades
For Custom Hex Bolt (GHJ Series) — GB/T 5783 / ISO 4017 (Series 009), 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 Custom Hex Bolt (GHJ Series) — GB/T 5783 / ISO 4017 (Series 009) Available in Grade 8.8 Steel
| Size designation | Outer diameter / width (mm) | Length / height (mm) | Bore / thread (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| Size 1 | 10 | 20 | 6 | C45 carbon steel | GB/T 1804-m |
| Size 2 | 12 | 25 | 8 | C45 carbon steel | GB/T 1804-m |
| Size 3 | 16 | 32 | 10 | C45 carbon steel | GB/T 1804-m |
| Size 4 | 20 | 40 | 12 | C45 carbon steel | GB/T 1804-m |
| Size 5 | 25 | 50 | 16 | C45 carbon steel | GB/T 1804-m |
| Size 6 | 32 | 63 | 20 | C45 carbon steel | GB/T 1804-m |
| Size 7 | 40 | 80 | 25 | C45 carbon steel | GB/T 1804-m |
| Size 8 | 50 | 100 | 30 | C45 carbon steel | GB/T 1804-m |