Property Class 8.8 Steel Jam Nuts (Thin Hex, Inch) combine the dimensional form of ASME B18.2.2 with the material properties of grade ISO 898-1 property class 8.8: requires plating (zinc) for corrosion protection, magnetic, service range commonly limited to approx. +300 °C; confirm against the coating and the load. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose Property Class 8.8 Steel for Jam Nuts (Thin Hex, Inch)
The workhorse medium-carbon alloy class for structural joints. For jam nuts (thin hex, inch), 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 jam nuts (thin hex, inch) 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 Jam Nuts (Thin Hex, Inch), 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 Jam Nuts (Thin Hex, Inch) Available in Property Class 8.8 Steel
| Thread size | Across flats s (mm) | Across corners e (mm) | Nut height m (mm) | Across flats (in) | Nut height (in) | Reference standard |
|---|---|---|---|---|---|---|
| 1/4"-20 | 11.11 | 12.70 | 3.97 | 7/16 | 5/32 | ASME B18.2.2 |
| 5/16"-18 | 12.70 | 14.53 | 4.76 | 1/2 | 3/16 | ASME B18.2.2 |
| 3/8"-16 | 14.29 | 16.35 | 5.56 | 9/16 | 7/32 | ASME B18.2.2 |
| 7/16"-14 | 17.46 | 19.98 | 6.35 | 11/16 | 1/4 | ASME B18.2.2 |
| 1/2"-13 | 19.05 | 21.79 | 7.94 | 3/4 | 5/16 | ASME B18.2.2 |
| 9/16"-12 | 20.64 | 23.62 | 7.94 | 13/16 | 5/16 | ASME B18.2.2 |
| 5/8"-11 | 23.81 | 27.23 | 9.53 | 15/16 | 3/8 | ASME B18.2.2 |
| 3/4"-10 | 28.58 | 32.69 | 11.11 | 1-1/8 | 7/16 | ASME B18.2.2 |
| 7/8"-9 | 33.34 | 38.14 | 12.70 | 1-5/16 | 1/2 | ASME B18.2.2 |
| 1"-8 | 38.10 | 43.59 | 14.29 | 1-1/2 | 9/16 | ASME B18.2.2 |
| 1-1/8"-7 | 42.86 | 49.04 | 15.88 | 1-11/16 | 5/8 | ASME B18.2.2 |
| 1-1/4"-7 | 47.63 | 54.48 | 17.46 | 1-7/8 | 11/16 | ASME B18.2.2 |
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.
