For fine-thread hex flange nuts in Property Class 8.8 Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for Property Class 8.8 Steel (ISO 898-1 property class 8.8) is summarized below together with every size supplied.
Why Choose Property Class 8.8 Steel for Fine-Thread Hex Flange Nuts
The workhorse medium-carbon alloy class for structural joints. For fine-thread hex flange nuts, this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating (zinc) for corrosion 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.
Galvanic & Galling Considerations
For fine-thread hex flange 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 Fine-Thread Hex Flange Nuts Available in Property Class 8.8 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 8.8 Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
Grade 8 8 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.
