Hex nuts, threaded fasteners, are commonly utilized to fasten the end of a bolt. They are installed on a bolt's end once it has passed through two or more workpieces. The internal threading of hex nuts is supported by the external threading of bolts. Hex nuts typically have a hexagonal shape, providing six sides for easy gripping. The top four varieties include standard, slotted, capped, and flange nuts.

Hex nuts, also known as hexagon nuts, are fundamental components in various industrial settings. The term "hex" refers to the nut's six sides, providing stability and ease of use. These nuts with internal threading are commonly paired with machine thread bolts and screws when a locking mechanism is not required.