Lochkreisdiameter

Lochkreisdiameter, also called bolt circle diameter, is the diameter of the circle that passes through the centers of mounting holes on a circular flange or hub. It is a fundamental parameter for mounting components such as wheels, brake discs, and flanges, because it determines whether a given part can be fastened to a hub or flange.

It is typically expressed in millimeters and is paired with the number of holes in the bolt pattern, in the form N x D. The Lochkreisdiameter D is the distance across the bolt pattern circle. For example, a wheel described as 5x112 has five mounting holes arranged on a circle of 112 mm in diameter.

Common Lochkreisdiameters vary by vehicle type and region; European passenger cars often use 5x112 or 5x114.3, while other patterns such as 4x100 are common on compact cars. When selecting wheels or compatible brake rotors, both the Lochkreisdiameter and the center bore must match the hub. Mismatched bolt patterns will not fit without adapters, which may affect safety and alignment.

Note that the center bore (the hole at the wheel’s center) is a separate requirement: it should fit the hub’s diameter, and if it is larger, a centering ring may be used; if it is smaller, the wheel will not mount. The Lochkreisdiameter is defined by the hole placement and is independent of the bore size.