How to choose rim bolts?

Many people struggle with choosing the right wheel bolts for their car's rims. Learn the basic rules that should guide your choice.

Choosing the right bolts for your rim isn't difficult if you know what to look for. After reading the following few paragraphs, you'll be able to easily order bolts that perfectly fit your rim.

Why is selecting the right screws crucial for safety?

The type of bolts you use on your wheels is crucial to your vehicle's safety. Of course, if you order bolts with thread diameters that don't match, you simply won't be able to screw them in. However, that's the least of your worries, as you'll simply have to buy new ones. However, if you choose a bolt with the wrong mounting type or one with a thread length that's too short, it can mean the bolts will easily come loose on the road. And that's an exceptionally dangerous situation.

Rim bolts that are too long can also have a number of negative consequences. If they're even slightly too long, the protruding portion can corrode, making it difficult to remove later. If you overdo it by using rim bolts that are too long, you can damage braking components that come into contact with the protruding portion of the bolt. When selecting the bolt length for your rim, don't forget to factor in the added dimension of spacers , if any are used.

What are the most important features of good rim bolts?

Firstly, the bolts must be properly matched to the car and rim, as you'll read in the next section. The second consideration is the hardness of the bolt material. Here, the bolts must have a strength class of at least 10.9. A lower value of this parameter can mean the bolt will strip or its threads will be damaged. This can especially happen when tightening by feel without a proper torque wrench. A torque wrench should always be used in the workshop, but when changing a spare tire on the road, regular wheel wrenches carried in the trunk are usually used.

Another important feature of bolts is their corrosion resistance. These bolts are typically galvanized steel, which should be absolutely sufficient protection. They can also be chrome-plated or coated with various manufacturer-specific names. Bolts of unknown origin may not meet strength or corrosion resistance requirements, or even differ significantly in size from their specifications. Bolts ordered from a reputable shop will certainly provide long-lasting, reliable service in your car.

What should you consider when selecting rim bolts?

When selecting wheel bolts, you should follow the exact requirements specified by the manufacturers of your car and wheels if you have replaced them with non-factory ones.

These are the following points:

• types of screw heads
• screw thread diameter
• screw thread pitch
• screw thread length
• screw hardness – class at least 10.9;
• corrosion resistance – galvanizing, chrome plating or other types of coatings;
• wrench size – usually 17 or 19 – these are the wheel wrenches that come with every car.

Possible rim bolt head types are:

• conical;
• spherical, ball, cylindrical;
• flat.

In sports solutions, studs are often used instead of screws. These, in turn, are then screwed onto the mounting nuts , which must also have the correct end type to fit the specific rims. This solution shortens wheel change times, which is crucial in racing.

Floating-head bolts, also known as floating cone bolts, are also sometimes used. These bolts can be used to correct minimal differences in wheel bolt spacing. This difference should not exceed two millimeters, meaning, for example, instead of a 4x100 bolt spacing, a 4x98 bolt spacing can be installed. They are also available as floating-nut studs.

Floating bolts or floating nuts can be used on both steel and aluminum rims. In the latter case, they can also be used with the correct hole spacing without affecting the quality of the connection. Some mechanics recommend always mounting aluminum rims this way.

Which bolts for aluminum rims?

Aluminum rims require the use of appropriate bolts for installation. These are typically conically seated bolts, and their bolt heads must be conically designed. Aluminum rim bolts are often also made with a smaller head to reduce the risk of scratching the rim during installation or removal. Scratches in aluminum rims are dangerous and can develop into cracks over time.

Which bolts are for steel rims?

Steel rims typically use spherical bolts. Some cars, particularly those from Stellantis, formerly PSA, such as Citroen and Peugeot, also use flat-set bolts.

You should choose the same nuts if your car has studs instead of bolts.

Is it worth investing in anti-theft screws?

Anti-theft wheel bolts have been a well-known security feature for years. They were most popular in the 1990s, when thefts of both entire cars and their components were rampant. This is much less of a problem today, but such incidents still occur, especially if you have to leave your car in poorly lit and unattended areas. Remember that these bolts must meet the same requirements as all other wheel bolts.

Such wheel bolt sets should usually include one for each wheel, along with wheel wrenches for unscrewing the unusual shape of the bolt. The more unusual the shape, the less likely someone will be able to unscrew it without a special wrench. Usually, they won't even try, instead opting for a less secure car. Anti-theft bolts are still very useful, but they require remembering to always have special wheel wrenches ready in the trunk, as you never know when you'll need them.

What are the markings of rim bolts?

Selecting rim bolts for your rims means reading their descriptions in the online store. Typical designations you might encounter in rim bolt descriptions include:

mounting screw M15 x 1.25 sphere 35 mm key 17

This means, respectively:

• screw thread diameter – M15
• screw thread pitch – 1.25
• thread length – 35 mm
• type of head (setting, also incorrect underpinning) – spherical (ball)
• screw wrench size – 17.

Additionally, the hardness class should also be specified, as well as whether the screw is galvanized, chrome-plated, or otherwise protected against corrosion. The screw itself may not have any markings, although it most often includes a hardness marking, and sometimes also the screw thread diameter and thread pitch.

Select your rim bolts according to the parameters listed above, and you'll be satisfied and they'll serve you well for a long time. Avoid shady garages where inexperienced people change wheels. This is a crucial step that has a huge impact on driving safety. Choosing the right rim bolts is just the beginning; it's crucial to install them correctly, check them, and adjust them if necessary after the first 50 to 100 kilometers. Only then will you be sure that nothing will surprise you on the road and that your ride will be completely safe.