The bolt pattern is the diameter of an imaginary circle in the center of the wheel lugs, bolt patterns can be 4,5,6 & 8 lugs. The diagram below shows how to measure the bolt pattern 6 & 8 lug are done the same as the 4 lug.
The center bore is the hole machined in the center of the wheel. Some wheels are machined to match the vehicle that would make it a hub centric wheel.
The offset is the distance from center of the wheel to the mounting pad If the mounting pad is in front of the center of the wheel it is a positive wheel If the mounting pad is in back of the center of the wheel it is a negative wheel If the mounting pad is in the center of the wheel it is a 0 offset wheel.
Back space is the distance from the outer back lip to the mounting pad. The best way to check back space is to lay the wheel face down and lay a straight edge across the back lip and measurer to the mounting pad.
See diagram below for proper tightening of lugs:
Stud Size | Torque in ft/lbs | Number of turns |
---|---|---|
12 x 1.5 mm | 70 - 80 | 6,5 |
12 x 1.25 mm | 70 - 80 | 8 |
14 x 1.5 mm | 85 - 90 | 7,5 |
14 x 1.25 mm | 85 - 90 | 9 |
7/16 in. | 70 - 80 | 8 |
1/2 in. | 75 - 85 | 8 |
9/16 in. | 135 - 145 | 8 |