How to choose wheel bolts?

Many people have a problem with which bolts to choose for the rims of their car. Learn the basic rules that you should follow when making this choice.

Choosing wheel bolts is not difficult if you know what to look for. After reading a few paragraphs below, you will be able to easily order screws that perfectly match your rim.

Why is the selection of the right screws crucial for safety?

What bolts you use in your wheels is of great importance for the safety of driving a car. Of course, if you order screws in which the thread diameter of the screw does not match, you simply will not be able to screw them in. However, this is the least of the problems, because you will simply have to buy new ones. However, in the case of selecting a screw with the wrong type of setting or where the length of the thread is too small, it may mean the danger of easy unscrewing of the screws on the road. And this is an extremely dangerous thing.

Rim bolts that are too long can also cause a lot of negative consequences. If they are only slightly too long, the protruding part may corrode, making it difficult to remove such a screw later. If you overdo it too much, using wheel bolts that are too long, you can damage the brake system components that come into contact with the protruding part of the bolt. When choosing the length of the bolt for your rim, do not forget to add the dimension added by the spacers , if you used them.

What are the most important features of good wheel bolts?

Firstly, the bolts must be properly matched to the car and the rim, which you will read about in the next paragraph. The second issue is the hardness of the material from which the screw is made. Here it is necessary that the bolts have a strength class of at least 10.9. A lower value of this parameter may mean that the screw will be broken or its thread will be damaged. This can happen especially when tightening by feel without using a proper torque wrench. In the workshop, it should always be used, but when changing a spare wheel on the road, ordinary wheel wrenches carried in the trunk are usually used.

Another important feature of screws is their resistance to corrosion. Here, as standard, these are galvanized steel screws, which should be absolutely sufficient protection. They can also be chrome-plated screws or covered with coatings with various proper names of given manufacturers. Screws of unknown origin may not meet the strength requirements, corrosion resistance or even differ too much in size from what is declared in their description. Mounting bolts ordered in a good store will certainly serve your car for a long time and properly.

What to consider when choosing wheel bolts?

When selecting bolts for the rim, you should follow the exact requirements provided by the car and rim manufacturers, if you replaced them with non-factory ones.

These are the following points:

• screw head types
• 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 - such wheel wrenches are equipped with every car.

Possible rim screw head types are:

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

In sports solutions, pins are often used instead of screws. On them, in turn, fastening nuts are screwed on, which must also have the right type of ending matching the rims. This solution allows you to shorten the time of changing the wheel, which is of great importance in racing.

Floating head screws, also known as floating cone screws, are also sometimes used. Such bolts can be used to correct minimal differences in the spacing of the rim holes. Such a difference should not exceed two millimeters, i.e., instead of a 4 × 100 spacing, 4 × 98 can be installed. They are also available as floating nut studs.

Floating bolts or floating nuts can be used for both steel and aluminum rims. In the latter case, they are also used with the correct spacing of the holes, without affecting the quality of the connection. Some mechanics recommend that alloy wheels should always be fitted this way.

Which bolts for alloy wheels?

Aluminum rims require the use of appropriate bolts to tighten them. These are usually tapered screws, and the screw heads must be tapered. Bolts for aluminum rims are also often made with a smaller head to ensure less risk of scratching the rim during assembly or disassembly. Scratches in aluminum rims are dangerous and can develop into cracks during operation.

Which bolts for steel rims?

Steel rims are ball screws (spherical) as standard. In some cars, especially from the Stellantis concern, formerly PSA, i.e. Citroen and Peugeot, flat-mounted bolts are also used.

Similarly, nuts should be selected if your car has studs instead of bolts.

Is it worth investing in anti-theft screws?

Anti-theft wheel bolts are a protection known for years. They were the most popular in the nineties of the last century, when the number of thefts, both of whole cars and their parts, was enormous. It's much less of a problem now, but it still happens. Especially if you have to leave your car in poorly lit and unguarded places. Remember that such a bolt must meet the same requirements as all other rim bolts.

Such sets of bolts, usually one for each wheel, should also include wheel wrenches to unscrew the unusual shape of a given bolt. The weirder the shape, the less chance someone can unscrew it without a special key. Usually, he won't even try, he'll just take care of the less secure car. Anti-theft bolts are still very useful, just remember to keep special wheel wrenches in the boot, as you never know when you'll need them.

What are the designations of wheel bolts?

Choose wheel bolts, i.e. read their description in the online store. Typical markings that can be found in such a description of wheel bolts are, for example:

fixing screw M15 x 1.25 sphere 35 mm wrench 17

This means in turn:

• screw thread diameter - M15
• screw thread pitch - 1.25
• thread length - 35 mm
• type of head (setting, also incorrectly set) - spherical (ball)
• wrench size for screwing - 17.

In addition, the hardness class should also be specified and whether the screw is galvanized, chrome-plated or otherwise protected against corrosion. There may be no markings on the screw itself, although it is most often marked with a hardness marking, sometimes also the diameter of the screw thread or the pitch of the thread.

Choose wheel bolts according to the parameters given above, and you will be satisfied and they will serve you for a long time and without any problems. Also, avoid dubious workshops where random people with no experience do wheel changes. This is a very important activity that has a huge impact on driving safety. The selection of wheel bolts is only the beginning, the key is to install them correctly, as well as check and correct if necessary after driving the first 50 to 100 kilometers. Only then will you be sure that nothing will surprise you on the road and your driving will be completely safe.