The Anatomy of a Wheel

While a wheel might seem relatively simple, they are actually very precise parts that are built under strict guidelines in order to help your car drive more smoothly, more safely, and handle better. We want to give you a tour of the different parts of a modern wheel so you know what you’re putting on your car!

Check out the graphic on this page and read the information below to get a basic understanding of the different parts of a wheel. When you’re ready to buy a new set, shop with us here at Wheel Specialists. We have provided our customers with great prices and a great selection for years!

The Barrel

The barrel is the cylindrical part of the wheel. It gives the wheel its shape and is the section between the inward and outward faces.

The Rim

While some people refer to wheels as “rims,” the rim is actually the part of the wheel that makes contact with the tire. The rim is where you size a wheel. For example, if a rim measures 21” in diameter, you are looking at a 21” wheel.

Wheel Plate

The wheel plate is the area surrounding the central bore. It will have holes in it (called the bolt circle) for the lugs to fit in. You’ll need to pay attention to ensure that the wheel has the same number of holes in the bolt circle as the vehicle has bolts. The number of bolts is part of the PCD (see below).

Center Bore

The center bore is the hole in the very center of the wheel. Usually it is covered on the outside by a cap.

Pitch Circle Diameter (PCD)

The PCD is the diameter of bolt circle. The diameter, along with the number of bolts, forms a wheel’s PCD. A wheel with six bolts and a diameter of 120 mm would have a PCD of 6/120.


The spokes give a wheel strength as well as style. The spokes and the wheel plate come together to keep the wheel strong and usable. The spokes are also used to change the look of a wheel. While some high end wheels feature incredibly elaborate spokes, many wheels that come standard are less flashy.

What are Wheels Made From?

Modern wheels are generally made from steel or steel alloys, and materials that are lighter than steel. Manufacturers spend a lot of time and money on researching the best new materials that will give your wheels the strength they need to be able to put up with the harsh conditions of driving without being excessively heavy.

If you own a truck or SUV, you’ll need to make sure that your wheels are strong enough to handle the extra weight and abuse a truck undergoes. While your options for cars are less limited, be aware that buying the lightest wheels possible may mean they are less strong and that you may have to replace them more often.

Armed with this new knowledge, grab the perfect set of new wheels for your vehicle today at Wheel Specialists! We carry a huge selection at great prices, so you’re sure to find exactly what you need to make your car handle and look better than ever before!