EdupradaTightening torque comes into play when it is necessary to mount one or more wheels on your vehicle. They are held in place at the rim with bolts, each of which requires a precise turning force. This phenomenon is referred to as tightening torque.
What is wheel tightening torque?
When you change a wheel , it is necessary to attach the new wheel to its hub. This is done through a bolt assembly consisting of a stud or screw as well as a nut . Thanks to this system, the wheel can be stationary and there will be no play that could be created.
Depending on the model, you can find 4 to 5 bolts to assemble on a wheel . As a bolt is based on the application of a force in order to bring two elements together, this tension must be perfectly calculated so that the parts, through friction, do not move.
This tension force which applies to the bolt is linked to that applied to the nut, we therefore speak of tightening torque. It is therefore applied to an axis and is expressed in Newton meters (Nm) . For example, 10 Nm = a rotational force of 1 kilo for a lever of 1 meter.
This tightening torque will therefore vary from one vehicle to another but also depending on the type of wheel it has. Generally, it varies depending on the following:
- The construction material of the rim ;
- The diameters of the nut and the screw or stud;
- The pitch of the screw or stud;
- The coefficients of friction at the level of the thread and the nut.
What tightening torque for an aluminum wheel?
If your car has wheels with aluminum alloy rims, you will need to adjust the tightening torque as it will be different from that of a steel rim . As a general rule, for an aluminum wheel , here are the most common bolt sizes:
- A 10 mm diameter bolt : the tightening torque is around 72 Nm;
- A 12 mm diameter bolt : it is approximately 96 Nm;
- A 14 mm diameter bolt : it should be approximately 132 Nm
Concerning steel rims, the tightening torque is generally 20% lower than the values for an aluminum rim. When in doubt, always refer to your manufacturer’s recommendations provided in your car’s maintenance booklet.
This will give you access to the tightening torque values recommended by the manufacturer to ensure optimal operation of your vehicle.
Can you tighten a wheel without a torque wrench?
Not all motorists looking to change their wheel are equipped with a torque wrench to carry out this maneuver. However, it is essential to facilitate disassembly and ensure the tightening torques recommended by your manufacturer while not damaging the wheels or their fixing axles.
Additionally, without a torque wrench, you have no way to be sure that the torque is uniform across all nuts and bolts. This can therefore put you in danger when traveling.
If you do not carry out this operation with a torque wrench, you will have to go to a professional workshop so that they can check the tightening torque of the wheels.
It is also necessary to take into account the order of assembly and disassembly of the bolts which vary depending on their number. So, when you embark on this intervention, remember to respect the order indicated in the diagram above.
Where to find the tightening torque table for a car wheel?
The tightening torque table can be found in your vehicle’s maintenance booklet . If you do not have it, you can find the most common recommendations in the table below.
| Thread | Tightening torque for a steel wheel | Tightening torque for an alloy wheel |
|---|---|---|
| Thread with a diameter of 10 mm | 50 to 60 Nm | 60 to 70 Nm |
| Thread M 12/1.25 | 50 to 70 Nm | 60 to 80 Nm |
| Thread M 12/1.5 | 80 to 100 Nm | 100 to 120 Nm |
| Thread M 14/1.5 | 110 to 130 Nm | 120 to 140 Nm |
These values are for information only, they can vary significantly depending on the characteristics of the axis, whether it is smooth or has splines.
The tightening torque of a wheel is a value to know and should not be calculated approximately at the risk of encountering significant wheel geometry problems and a lack of grip on the road during your journeys.