For weld studs (cd and drawn-arc) in Property Class 12.9 Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for Property Class 12.9 Steel (ISO 898-1 property class 12.9) is summarized below together with every size supplied.
Why Choose Property Class 12.9 Steel for Weld Studs (CD and Drawn-Arc)
The highest common strength class, for high-load machine assembly. For weld studs (cd and drawn-arc), this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 12.9 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating or black-oxide protection |
Corrosion Behavior in Service
Carbon and alloy steel weld studs (cd and drawn-arc) 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 weld studs (cd and drawn-arc) 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 Weld Studs (CD and Drawn-Arc) Available in Property Class 12.9 Steel
| Thread size | Length L before weld (mm) | Weld process | Burn-off (mm) | Minimum sheet thickness (mm) | Flange diameter (mm) | Material | Reference standard |
|---|---|---|---|---|---|---|---|
| M3 | 8 | CD (type PT) | 0.5 | 0.6 | — | Mild steel / A2 | ISO 13918 |
| M4 | 10 | CD (type PT) | 0.5 | 0.7 | — | Mild steel / A2 | ISO 13918 |
| M5 | 16 | CD (type PT) | 0.5 | 0.8 | — | Mild steel / A2 | ISO 13918 |
| M6 | 20 | CD (type PT) | 0.5 | 1.0 | — | Mild steel / A2 | ISO 13918 |
| M8 | 25 | Drawn-arc (type PD) | 4.0 | 2.0 | 13.0 | Mild steel | ISO 13918 |
| M10 | 30 | Drawn-arc (type PD) | 4.0 | 2.5 | 16.0 | Mild steel | ISO 13918 |
| M12 | 40 | Drawn-arc (type PD) | 5.0 | 3.0 | 19.0 | Mild steel | ISO 13918 |
Dimensions are independent of the material: every size above is available in Property Class 12.9 Steel.
Custom manufacturing · Made to drawing
Need this bolt in a grade that is not listed?
Grade 12 9 Steel is one of the grades the catalog describes. A non-standard bolt is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.







