● Bolt: A type of fastener consisting of a head and a screw (cylindrical body with external threads), which needs to be matched with a nut to securely connect two parts with through holes.

Nail: It is also a type of fastener composed of a head and a screw, which should be used in situations with smaller apertures for secure installation.

● Nuts: with internal threaded holes, generally in the shape of flat Hexagonal prism columns, and also in the shape of flat square columns or flat cylinders, which are used to fasten and connect two parts together with bolts, studs or machine screws to make them become a whole.

Circle: A type of fastener with a flat circular shape. Placed between the support surface of bolts, screws, or nuts and the surface of the connecting parts, it plays a role in increasing the contact surface area of the connected parts, reducing pressure per unit area, and protecting the surface of the connected parts from damage; Another type of elastic washer can also prevent the nut from loosening.

● Pins: mainly used for positioning parts, some can also be used for connecting, fixing parts, transmitting power, or locking other fasteners.

Nail: A type of fastener consisting of a head and a nail rod, used to fasten and connect two parts (or components) with through holes, making them a whole. This type of connection is called rivet connection, abbreviated as riveting. Belonging to non detachable connections. Because to separate the two parts connected together, it is necessary to break the rivets on the parts.

Screw: It is also a type of fastener composed of two parts: the head and the screw, which can be divided into three categories according to their purpose: machine screws, set screws, and special purpose screws. Machine screws are mainly used for the fastening connection between a part with a threaded hole and a part with a through hole, without the need for nut coordination (this connection form is called screw connection, which is also a detachable connection; it can also be used with a nut for the fastening connection between two parts with through holes.) Set screws are mainly used to fix the relative position between two parts. Special purpose screws, such as eyebolts, are used for lifting parts.