Lug Nut
A specialized threaded fastener used to secure a wheel onto a vehicle's wheel studs.
Lug nuts are heavy-duty, internal-threaded fasteners that screw onto wheel studs to secure the wheel and tire assembly to the vehicle hub. They feature a tapered or chamfered seat (conical, ball, or flat) that aligns with the mounting holes of the wheel, ensuring the wheel is perfectly centered and clamped with even pressure.
Lug nuts must be tightened to the manufacturer's specific torque specification using a torque wrench. Over-tightening can strip the threads or warp the brake rotors, while under-tightening can cause the lug nuts to back off, leading to a loose wheel and potential wheel detachment.
Common variations include chrome-plated nuts, open-ended nuts for steel wheels, and locking lug nuts designed to prevent wheel theft.