I wanted something strong and light for the racer. I wanted something with a nut that remained tight. I chose AN nuts and bolts, which are used in aviation and military applications. They have worked well.
For the hub bolt itself, the AN bolts have the correct length grip (the length of the solid shank). If the shank is instead fully threaded, it may work fine, but the fastener is not designed to deal with maximum shear on the threaded portion of the bolt.
Nyloc nuts are generally quite good. I have used them with good results. However, they are not allowed in racing, military, or aviation applications, which should give some type of hint as to their use. On a motorcycle, they work well at resisting loosening under vibration. On the Junker vibration machinery, which is designed to test a nuts resistance to turning, they do not work. They unscrew at the same rate as a plain nut. The one saving grace is that the nut quickly backs off its torque, but the nut does have enough friction to remain on the bolt. Thus, you will not lose the loose nut.
The Nyloc nuts are not used because various inspectors (race techs, FAA, or Military) cannot tell if the nut has been used more than once. It is a use-once-and-throw-it-away item. That is often hard to do as a builder.
The bolt I use is AN5-7A, an undrilled 5/16 x24 with the correct shank and thread length.
The lock nuts are MS210042-5. Then nuts are quite small. They use a wrench that is two sizes smaller than the wrench used on a 5/16" nut. This makes assembly a bit easier.
In the US, this hardware can be purchased at Pegasus Racing.
At Pegasus, our huge inventory of AN and Mil-Spec hardware and aircraft fasteners is always expanding. We also stock latches, quarter-turn fasteners, Cleco clamps, and many more special racing parts.
www.pegasusautoracing.com
I would not worry too much about the decision. Most options seem to work well in practice.
David
