Property Class 12.9 Steel Self-Clinching Press-Fit Nuts are supplied to our own published dimensions — this is a trade-series article rather than one covered by a dimensional standard, so confirm the figures against the part you are replacing. The grade provides requires plating or black-oxide protection and is magnetic; the practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load.
Why Choose Property Class 12.9 Steel for Self-Clinching Press-Fit Nuts
The highest common strength class, for high-load machine assembly. For self-clinching press-fit 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 |
Galvanic & Galling Considerations
For self-clinching press-fit 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.
Comparable Grades
For Self-Clinching Press-Fit Nuts, class 8.8 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 Self-Clinching Press-Fit Nuts Available in Property Class 12.9 Steel
| Thread size | Shank diameter (mm) | Length (mm) | Hole in sheet (mm) | Minimum sheet thickness (mm) | Maximum sheet hardness | Material | Installation |
|---|---|---|---|---|---|---|---|
| M3 | 4.20 | 3.30 | 4.22 | 0.8 | HRB 80 | Case-hardened steel | Press, squeeze |
| M4 | 5.40 | 3.80 | 5.42 | 0.8 | HRB 80 | Case-hardened steel | Press, squeeze |
| M5 | 6.35 | 4.20 | 6.38 | 1.0 | HRB 80 | Case-hardened steel | Press, squeeze |
| M6 | 7.95 | 4.80 | 7.98 | 1.0 | HRB 80 | Case-hardened steel | Press, squeeze |
| M8 | 9.55 | 5.70 | 9.58 | 1.5 | HRB 80 | Case-hardened steel | Press, squeeze |
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.
