I think the lug bolts are made of softer metal. Once a local tire-shop did a tire rotation for me and stripped the thread on one of the bolts so that it spins and spins in either direction but won't tighten nor come out. Took it back for them to fix they had to re-thread the receiving end and use a new bolt. The tech. who did the work swore he "finger-tightened" the bolt before he used the air-hammer but I think he was using the bolt as a "hanging pin" to hold the heavy wheel therefore stripped both ends of the thread.

You'd think people working with tires and wheels all day long know how to handle mounting and dismounting wheels.