Material specification page for fine-thread hex flange 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 ISO 10663.
Why Choose Property Class 12.9 Steel for Fine-Thread Hex Flange Nuts
The highest common strength class, for high-load machine assembly. For fine-thread hex flange 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 fine-thread hex flange 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 Fine-Thread Hex Flange 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 Fine-Thread Hex Flange Nuts Available in Property Class 12.9 Steel
| Size | Pitch P (mm) | c_min (mm) | d_a_max (mm) | d_a_min (mm) | d_c_max (mm) | d_w_min (mm) | Width across corners e (mm) | Nut height m (mm) | m_min (mm) | m_w_min (mm) | Width across flats s (mm) | s_min (mm) | r_max (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M8x1 | 1 | 1.2 | 8.75 | 8 | 17.9 | 15.8 | 14.38 | 8 | 7.64 | 4.6 | 13 | 12.73 | 0.5 | ISO 10663 |
| M10x1.25 | 1.25 | 1.5 | 10.8 | 10 | 21.8 | 19.6 | 16.64 | 10 | 9.64 | 5.6 | 15 | 14.73 | 0.6 | ISO 10663 |
| (M10x1) | 1 | 1.5 | 10.8 | 10 | 21.8 | 19.6 | 16.64 | 10 | 9.64 | 5.6 | 15 | 14.73 | 0.6 | ISO 10663 |
| M12x1.25 | 1.25 | 1.8 | 13 | 12 | 26 | 23.8 | 20.03 | 12 | 11.57 | 6.8 | 18 | 17.73 | 0.7 | ISO 10663 |
| (M12x1.5) | 1.5 | 1.8 | 13 | 12 | 26 | 23.8 | 20.03 | 12 | 11.57 | 6.8 | 18 | 17.73 | 0.7 | ISO 10663 |
| (M14x1.5) | 1.5 | 2.1 | 15.1 | 14 | 29.9 | 27.6 | 23.36 | 14 | 13.3 | 7.7 | 21 | 20.67 | 0.9 | ISO 10663 |
| M16x1.5 | 1.5 | 2.4 | 17.3 | 16 | 34.5 | 31.9 | 26.75 | 16 | 15.3 | 8.9 | 24 | 23.67 | 1 | ISO 10663 |
| M20x1.5 | 1.5 | 3 | 21.6 | 20 | 42.8 | 39.9 | 32.95 | 20 | 18.7 | 10.7 | 30 | 29.16 | 1.2 | ISO 10663 |
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.
