Material specification page for square weld nuts in Property Class 12.9 Steel. Covers the grade designation (ISO 898-1 property class 12.9), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to DIN 928.
Why Choose Property Class 12.9 Steel for Square Weld Nuts
The highest common strength class, for high-load machine assembly. For square weld 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 square weld 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.
Comparable Grades
For Square Weld 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 Square Weld Nuts Available in Property Class 12.9 Steel
| Size | Pitch P (mm) | b (mm) | d2 (mm) | d4 (mm) | h1 (mm) | h2 (mm) | Nut height m (mm) | Width across flats s (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|
| M4 | 0.7 | 0.8 | 5 | 6.4 | 0.6 | 0.85 | 3.5 | 7 | DIN 928 |
| M5 | 0.8 | 1 | 6 | 8.2 | 0.8 | 1.05 | 4.2 | 9 | DIN 928 |
| M6 | 1 | 1.2 | 7.5 | 9.1 | 0.8 | 1.25 | 5 | 10 | DIN 928 |
| M8 | 1.25 | 1.5 | 10 | 12.8 | 1 | 1.55 | 6.5 | 14 | DIN 928 |
| M10 | 1.5 | 1.8 | 12.5 | 15.6 | 1.2 | 1.725 | 8 | 17 | DIN 928 |
| M12 | 1.75 | 2 | 13.5 | 17.4 | 1.4 | 2.375 | 9.5 | 19 | DIN 928 |
| (M14) | 2 | 2.5 | 16.8 | 20.4 | 1.4 | 2.475 | 11.4 | 22 | DIN 928 |
| (M16) | 2 | 2.5 | 18.8 | 22.4 | 1.6 | 3 | 13 | 24 | DIN 928 |
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. Locking method is specifiable independently of the rest: nylon insert, all-metal deformed thread, serrated flange, or none. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
