A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads' friction (with slight elastic deformation), a slight stretching of the bolt, and compression of the parts to be held together.
There are various types, such as hex nuts and square nuts. Hex nuts are most commonly used in conjunction with hexagon bolts. Slotted nuts are mainly refers to the hexagonal slotted nut, that is, a slot is machined on the hexagonal nut. It is used in conjunction with screw bolts with holes and split pins to prevent relative rotation of bolts and nuts. Lock nut refers to the nut with locking function, including nylon insert hexagon lock nut and all-metal hexagon lock nut.
