Property Class 8.8 Steel Wheel Lug Nuts are supplied to ISO 898-1 property class 8.8. Corrosion behaviour is requires plating (zinc) for corrosion protection, the material is magnetic, and the usable service range is commonly limited to approx. +300 °C; confirm against the coating and the load. In practice this grade is the workhorse medium-carbon alloy class for structural joints.
- Grade
- ISO 898-1 property class 8.8
- Corrosion resistance
- Requires plating (zinc) for corrosion protection
- Magnetic response
- Magnetic
- Service temperature
- commonly limited to approx. +300 °C; confirm against the coating and the load
Property values are typical for the grade. Certified mechanical test data is available on request for production orders.
Material page for wheel lug nuts in Property Class 8.8 Steel (ISO 898-1 property class 8.8). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is requires plating (zinc) for corrosion protection and the service range is commonly limited to approx. +300 °C; confirm against the coating and the load.
Why Choose Property Class 8.8 Steel for Wheel Lug Nuts
The workhorse medium-carbon alloy class for structural joints. For wheel lug 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 wheel lug 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 Wheel Lug 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 Wheel Lug Nuts Available in Property Class 8.8 Steel
| Thread size | Hex size (mm) | Overall length (mm) | Seat | End form | Thread hand | Material |
|---|
| M12-1.50 | 21 | 33.5 | 60-degree conical | closed-end acorn | right-hand | steel |
| M12-1.50 | 21 | 36.45 | conical | closed-end acorn | right-hand | steel |
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.
Custom nut manufacturingSend a drawing
Applications & Industries
Where Wheel Lug Nuts are used, and what decides the specification in each case.
Industries that specify Wheel Lug Nuts
-
Automotive wheel service
Acorn lug nuts clamp a wheel against a conical hub seat.
-
Passenger vehicles
M12-1.50 and 21 mm hex examples cover the documented service part.
-
Fleet maintenance
Closed ends protect the thread from road debris.
-
Wheel repair
Seat angle and overall length are checked against the wheel.
-
Steel fabrication
Bolted structural and frame connections.
-
Automotive & transport
Vibration-prone joints where the locking type is specified on the drawing.
Typical applications
- clamping a wheel on a 60-degree conical seat
- matching M12-1.50 pitch and 21 mm hex
- choosing the 33.5 or 36.45 mm documented length
- checking closed-end clearance at the stud
- completing a bolted joint on a stud, rod or bolt
- locking an adjustment so it cannot drift
Service conditions to specify against
- Marine and coastal
- Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- High load
- Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- Match the class
- A nut below the bolt property class strips before the bolt reaches its own limit — pair class 8 nuts with 8.8 bolts, class 10 with 10.9.
Where to use something else
- Do not use an acorn lug nut on a wheel with a different seat form; a correct thread does not make an incorrect seat safe.
Full application guide: where Wheel Lug Nuts are used, how to specify them, and the cases they are wrong for
