For wire rope in Grade 12.9 Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for Grade 12.9 Steel (class 12.9) is summarized below together with every size supplied.
Why Choose Grade 12.9 Steel for Wire Rope — GB/T 6170 / ISO 4032 (Series 063)
The highest common strength class, for high-load machine assembly. For wire rope — gb/t 6170 / iso 4032 (series 063), this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 12.9 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating or black-oxide protection |
Corrosion Behavior in Service
Carbon and alloy steel wire rope — gb/t 6170 / iso 4032 (series 063) 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 wire rope — gb/t 6170 / iso 4032 (series 063) 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 Wire Rope — GB/T 6170 / ISO 4032 (Series 063) Available in Grade 12.9 Steel
| Nominal diameter (mm) | Construction | Min breaking force (kN) | Mass (kg/100m) | Material | Reference standard |
|---|---|---|---|---|---|
| 4 | 6x7 | 8.95 | 5.85 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 5 | 6x7 | 13.4 | 8.94 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 6 | 6x19 | 17.6 | 13.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 8 | 6x19 | 31.3 | 23.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 10 | 6x19 | 48.5 | 36.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 12 | 6x19 | 69.5 | 52.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 16 | 6x37 | 119 | 89.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 20 | 6x37 | 185 | 138.0 | Galvanized steel | GB/T 20118 / ISO 2408 |
| 24 | 6x37 | 265 | 196.0 | Galvanized steel | GB/T 20118 / ISO 2408 |