bolt circle

A **bolt circle** refers to the circular pattern formed by the centers of bolt holes in a wheel, flange, or mechanical component. It is a critical measurement used to ensure proper alignment and compatibility between parts, such as wheels and hubs in automotive and machinery applications. The bolt circle diameter (BCD) or pitch circle diameter (PCD) is typically specified in millimeters or inches and is essential for selecting the right bolts or fasteners to secure components safely and effectively.