Wheel nut is a lock

Disc-Lock
Disc-Lock International hopes to reduce wheel-off incidences with its new Disc-Lock Safety Wheel Nut. The company says the product is the only vibration and shock-proof lug nut that “virtually eliminates” the risk of wheel losses from trucks.

Manufactured in Detroit, the Safety Wheel Nut is said to stay put longer with a positive locking system in the form of rising cams which are joined together to form one assembly. When subjected to shock or vibration, the interlocking cams of the nut rise against each other. As the angle of the cams is greater than the pitch angle of the thread on the stud, the company says, a wedging action takes place and the Disc-Lock Safety Wheel Nut will not come loose, keeping the wheel on the axle.