Wheel bolt pattern
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==Measuring bolt pattern or bolt circle== | ==Measuring bolt pattern or bolt circle== | ||
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− | + | Pitch circle diameter, PCD or bolt circle diameter, means the diameter of an imaginary circle that goes through the center of each of the wheel stud bolt holes on a wheel. The wheel stud bolts are fixed to either the brake drum or the disc brake rotor and protrude through the wheel when it is mounted to the drum or rotor (there are a few vehicles that use loose bolts instead of fixed studs, old Plymouths and Volkswagens). | |
− | The | + | The PCD can be expressed in mm or inches. The PCD can be found on any 5 lug wheel by measuring from the center of the wheel(the axle hole), to the center of one of the wheel stud holes, and then multiplying that measurement by two. This is difficult on the 5 hole wheel because it is hard to judge the exact center of the large axle hole in the wheel. |
− | + | It may be easier to check this measurement by placing a straight edge (popcicle stick etc.) across the outer edge of two of the wheel stud holes. Then measure from the center of the wheel hole that is opposite the two holes that the straight edge touches, to the inside (closest) edge of the straight edge. In other words you are measuring the distance from a straight line touching the outside of two wheel bolt holes, to the center of the opposite wheel bolt hole. This will be easier to actually measure since you don't have to guess where the center of the large hole in the wheel is, and will closely approximate the diameter of the imaginary circle (PCD)passing through all of the wheel bolt holes. | |
− | and more than likely | + | On a 4 lug wheel, determine the PCD by measuring across the center of the wheel, from the center of one lug bolt hole to the center of the opposite lug bolt hole. |
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+ | If you were to see an advertisement for wheels that read: 5 X 4.75 it would mean the following: | ||
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+ | The wheels have a 5 stud pattern or 5 holes, and the wheel has a 4.75 inch diameter pattern for the wheel stud bolt holes. This pattern diameter could also be expressed metrically as 120.65mm. These wheels would more than likely fit your Chevy passenger car. | ||