How Bolt Pattern is Measured
The bolt pattern, also known as the lug pattern or wheel bolt pattern, is a crucial factor in determining the compatibility of wheels with a vehicle. It refers to the spacing of the lug nuts or bolts that secure the wheel to the vehicle’s hub. Accurate measurement of the bolt pattern is essential to ensure a proper fit and safe installation. In this article, we will explore how bolt pattern is measured and the importance of this process.
The bolt pattern is typically measured in two ways: by counting the number of bolt holes and by measuring the distance between the bolt holes. Here’s a step-by-step guide on how to measure the bolt pattern:
1. Count the number of bolt holes: Begin by visually inspecting the wheel and counting the total number of bolt holes. This can be done by looking at the wheel from the side and identifying the lug nuts or bolts. Make sure to count all the holes, including any that may be covered by wheel covers or hub caps.
2. Measure the bolt circle diameter (BCD): Once you have counted the number of bolt holes, you will need to measure the diameter of the imaginary circle that passes through all the bolt holes. This can be done using a tape measure or a caliper. Place the tape measure or caliper at the center of the wheel and measure the distance to the outermost bolt hole. Multiply this distance by 2 to obtain the bolt circle diameter.
3. Calculate the bolt pattern: To calculate the bolt pattern, divide the bolt circle diameter by the number of bolt holes. For example, if the bolt circle diameter is 5.5 inches and there are 5 bolt holes, the bolt pattern would be 5.5 inches / 5 = 1.1 inches.
It is important to note that the bolt pattern is not the same as the bolt circle diameter. The bolt pattern is a measure of the spacing between the bolt holes, while the bolt circle diameter is the overall diameter of the circle formed by the bolt holes.
In addition to the number of bolt holes and the bolt circle diameter, the lug bolt size and lug bolt thread pitch also play a role in determining the compatibility of wheels with a vehicle. These specifications can be found in the vehicle’s service manual or by contacting the vehicle manufacturer.
In conclusion, accurately measuring the bolt pattern is essential for ensuring a proper fit and safe installation of wheels on a vehicle. By following the steps outlined in this article, you can determine the correct bolt pattern for your vehicle and select the appropriate wheels for a perfect match.
