An axle is the rod or shaft that connects the wheel and the vehicle. It rotates and supports the weight of the vehicle. An axle stud bolt is what keeps the axle connected to the stud.

A stud is a relatively long rod that is threaded on both ends; the thread may extend along the complete length of the rod. It usually has no head, and simply acts as a threaded rod onto which nuts can be attached.

Bolts are one of the most common basic hardware parts you can see in any industry–automotive, construction, agriculture, etc. Bolts definition is they are mechanical fasteners that connect different parts. Its parts include the head and a threaded cylindrical body. Bolts are usually used with washers and nuts to lock them in position and prevent loosening or crushing. One reason bolts are popular across all industries is that it makes assembly, disassembly, and reassembly easier compared to permanent fastening such as welding.

Bolts should not be confused with screws, however. As mentioned previously, bolts definition is they are mechanical fasteners that connect different parts. Screws are also mechanical fasteners; however, how they look and how they are used are different.