The bolt pattern is merely the number of bolts on the wheel. As the bolts will be evenly spaced, the number determines the bolt pattern. For example, most U.S. passenger cars have 5 bolts while compact models sometimes have only 4 and pick-up trucks can have as many as 6 or 8. If the bolt pattern for a wheel shows "blank" or "custom," it means it can be drilled to fit any bolt pattern.