Understanding Bolt Patterns

While many of us don’t give the wheels and how they attach to our vehicles much thought, a lot goes into keeping the wheels and tires secure so they don’t come off when we drive down the road. You’ve probably noticed the holes and lug nuts in the center of the wheel, but you might not know that not all wheels are the same, and they don’t all attach the same way. Here, we will take a look at what a bolt pattern is and how it works.

6 Lug Chevy Wheels

Chevy uses a six-lug bolt pattern for several of their SUVs and pickup trucks, and depending on which truck you have, the pattern is most likely a six-lug, 5.5-inch standard or medium offset. The six-bolt pattern is measured in a straight line from the center of the two bolt holes that sit directly across from each other. This is important to know when shopping for new wheels.

What Exactly Is a Bolt Pattern?

A bolt pattern, which is sometimes called a bolt circle, is the layout of the mounting holes for the wheel lugs. The pattern makes up the diameter of an imaginary circle formed by the center of the wheel lugs. You can see the bolt circle if you draw an imaginary line that passes through the center of each of the holes. A lug or lug nut is a fastener used to attach the wheel hub to the axle. It secures the wheel, centers it on the axle, and keeps it in place. Lug nuts are usually made with chrome-plated steel to keep them from corroding, but you can also find them in titanium or anodized aluminum if you want something lighter.

Two numbers state the bolt pattern. The first number is how many bolts, and the second number is the diameter of the imaginary circle. For example, the Chevy five-bolt pattern has five lug holes. If you see the pattern stated as 5-100 mm, it means there are five lugs, and the circle measures 100 mm in diameter.

In many cases, larger vehicles have more lugs, while smaller cars have fewer. It is important to know that the lug pattern has to match the pattern on the axle hub. Even a very small difference can cause the wheel to be off-center, which can create a vibration when you drive.

How Does a Bolt Pattern Work?

Not all bolt patterns are the same. Two different cars with the same number of lugs might not have the same pattern. Most manufacturers, such as Chevy, will use the same bolt pattern for all of their vehicles or use the same bolt pattern within their different classes of vehicles. As stated before, most Chevy trucks and SUVs use the Chevy six-lug bolt pattern.

Types of Bolt Patterns

The bolt patterns differ depending on the number of bolts. They include:

Four-Bolt Pattern

This pattern uses four lugs. The pattern is measured in a straight line from the center of the two bolt holes that sit across from each other.

Five-Bolt Pattern

Odd-numbered bolt patterns are a little more challenging to measure. Since they don’t have two holes that sit directly across from each other, you need to estimate the measurement. You can start by using a straight line from the back of one hole to the center of the third hole, but the only way to measure this type of bolt pattern accurately is to use a tool called a bolt pattern gauge or to have the training and knowledge to calculate the measurement using a geometric equation.

Six-Bolt Pattern

The six-bolt pattern is the Chevy bolt pattern size. Since it has an even number, you can measure it using the two bolts that sit directly across from each other.

Eight-Bolt Pattern

The eight-bolt pattern is often used by full-size SUVs, luxury vehicles, and midsize vehicles. It is one of the more common bolt patterns.

How Do I Find Out What My Bolt Pattern Is?

The best way to find out the bolt pattern for your Chevrolet is to speak with someone at the service center. Just tell the technician the make, model, and year of your vehicle, and they can tell you the exact bolt pattern.

How Important Is the Bolt Pattern?

When it comes to finding new wheels for your Chevy, the bolt pattern is one of the most important things to consider. Since the bolt pattern needs to match the pattern on the wheel, if you purchase aftermarket wheels and they don’t have the same pattern, they won’t fit.

What Other Factors Go Into Wheels and Attaching Them

In addition to the lug bolts and the bolt pattern, there are other specifications that must match when purchasing wheels, including:

  • Offset. The offset is the distance between the surface of the wheel where the hubs ascend and the centerline. The three types of offset include negative, positive, and zero. Zero offset means there is no distance between the centerline and the hub mounting surface. A positive offset has a hub mounting surface in front of the centerline or more toward the street, while a negative offset has a hub mounting surface behind the centerline or more toward the vehicle.
  • Center bore. The center bore is the machined hole that sits in the middle of the wheel. This center hole is where they fit the axle. Wheel manufacturers make wheels in such massive numbers that they don’t produce wheels for any specific car manufacturer. Since the different car manufacturers have different axle sizes, and this can’t change, you might need a hub ring to help make sure the wheel fits correctly.

If you need to find out more about wheels and the six-bolt pattern for your Chevy vehicle, give us a call at search our website. All the products that we offer can easily be searched using our filter or search module.