Wheel-Size.com

The centre bore is the size of the hole in the centre of the wheel where the spigot fits through.  The centre bore, (also known as spigot size), is the diameter of this hole, usually measured in millimetres.

PCD (Pitch Circle Diameter) is the measurement of the diameter of the imaginary circle drawn through all of the wheel bolts or studs on a wheel.  It is also known as the 'bolt circle'.

Here's a list of some random fun facts (trivia) about tires, rims and wheels, which you probably didn't know of before. Have fun with these, maybe it'll be a nice subject of discussion at work, dinner or at the gym or something like that! Most of the trivia is about tires and rims for cars, but other topics (vehicles) are also included.

 There are five main components to identify the correct lug nut or wheel lock: Thread Size Thread Pitch Seat Type Length/Dimensions Finish/Color