Property Class 8.8 Steel Elastomer-Sealing 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 (zinc) for corrosion 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 8.8 Steel for Elastomer-Sealing Nuts
The workhorse medium-carbon alloy class for structural joints. For elastomer-sealing 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 |
Galvanic & Galling Considerations
For elastomer-sealing 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 Elastomer-Sealing Nuts, class 10.9 or 12.9 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 Elastomer-Sealing Nuts Available in Property Class 8.8 Steel
| Thread size | Pitch (mm) | Sealing-rib height (mm) | Thread class | Temperature range (°C) | Finish |
|---|---|---|---|---|---|
| M3 | 0.5 | 0.2 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M4 | 0.7 | 0.3 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M5 | 0.8 | 0.4 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M6 | 1.0 | 0.5 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M8 | 1.25 | 0.6 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M10 | 1.5 | 0.6 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M12 | 1.75 | 0.8 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
| M14 | 2.0 | 6H | -75~+204 | zinc-chromate plated low-carbon steel |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in Property Class 8.8 Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
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. Height and across-flats are the two most often changed — a thinner nut for clearance, a larger hex for a tool that is already on the line. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
