Different brands – different bolt patterns
There are so many different brands of steering wheels out there and steering wheel hubs or hub adapters or boss kits depending on where you are in the world, plus quick release kits, hub extensions, eccentric ring spacers and most likely some more things. And as you might think or lets say hope, there should be a standard for the steering wheel bolt pattern or PCD (we’re coming to that abbreviation later). But, surprise, surprise, there isn’t. Some steering wheel manufacturers or brands do have the same bolt pattern which means you can bolt them together, but most of them don’t.
Some steering wheel brands or manufacturers even have different bolt patterns for different applications, means for different car brands like Ferrero for example does. Others have not only different bolt patterns, the amount of bolts are different. Some have just different bolt patterns for the use with different hubs. Not surprisingly, the largest and most well-known manufacturers, Momo and Nardi, have different bolt circles. But here, too, experts have already managed to screw a Momo steering wheel onto a Nardi hub. This can be done with a bit of filing, but in the interest of safety it should be avoided.
PCD – pitch circle diameter
Exactly, PCD stands for bolt circle diameter and describes nothing other than the diameter of the circle that goes through the center of all bolting holes, regardless of whether there are three, five, six or more bolts, as long as they are evenly spaced from each other. 6x70mm means there are 6 bolts in a diameter of 70mm. Since I keep getting questions about bolt circle diameters, this overview should answer most of these questions and show which products/manufacturers are interchangeable. And as always, if you have further questions, ask!
