Property Class 12.9 Steel (ISO 898-1 property class 12.9) is the highest common strength class, for high-load machine assembly. Specified on cage nuts (snap-in rack nuts) it determines the corrosion behaviour (requires plating or black-oxide protection) and the service temperature range (commonly limited to approx. +300 °C; confirm against the coating and the load); the dimensions are ours rather than a standard's, and are listed in full below.
Why Choose Property Class 12.9 Steel for Cage Nuts (Snap-In Rack Nuts)
The highest common strength class, for high-load machine assembly. For cage nuts (snap-in rack nuts), 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 cage nuts (snap-in rack nuts) 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 cage nuts (snap-in rack nuts) 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 Cage Nuts (Snap-In Rack Nuts) Available in Property Class 12.9 Steel
| Thread size | Square panel hole (mm) | Rail thickness (mm) | Cage width (mm) | Cage height (mm) | Retained nut | Material | Finish |
|---|---|---|---|---|---|---|---|
| M5 | 9.5 | 0.8~2.0 | 15.9 | 15.9 | Floating square | Spring steel | Zinc plated |
| M6 | 9.5 | 0.8~2.0 | 15.9 | 15.9 | Floating square | Spring steel | Zinc plated |
| M6 | 9.5 | 2.0~3.0 | 15.9 | 15.9 | Floating square | Spring steel | Black passivated |
| 10-32 | 9.5 | 0.8~2.0 | 15.9 | 15.9 | Floating square | Spring steel | Zinc plated |
| 12-24 | 9.5 | 0.8~2.0 | 15.9 | 15.9 | Floating square | Spring steel | Zinc plated |
| M8 | 12.0 | 1.0~2.5 | 19.0 | 19.0 | Floating square | Spring steel | Zinc plated |
Dimensions are independent of the material: every size above is available in Property Class 12.9 Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
Grade 12 9 Steel is one of the grades the catalog describes. Thread size is the obvious variable and rarely the interesting one — height for clearance, across-flats for the tool already in the cell, and the locking feature for the vibration actually present. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
