What Are the Classifications of Screw Hardware?

Generally refers to standard parts made of metal, which usually include the following 12 types of parts:

1.       Bolt:

A class of fasteners consisting of a head and screw (a cylinder with an external thread) that need to be combined with a nut to fasten and connect two parts with through holes. This form of connection is called a bolted connection. If the nut is screwed off the bolt, the two parts can be separated, so the bolt connection is a removable connection.

2.       Studs:

If there is no head, only one type of fasteners with threaded threads on both ends. When connected, one end must be screwed into a part with an internal threaded hole, the other end passes through the part with a through hole, and then the nut is screwed, even if the two parts are fastened into a whole. This form of connection is called a stud connection and is also a removable connection. Mainly used in the case of one of the connected parts with a large thickness, a compact structure, or due to frequent removal, it is not appropriate to use bolted connections.

3.       Screw:

It is also a type of fasteners consisting of the head and screw, which can be divided into three categories by purpose: machine screws, fastening screws and special purpose screws. Machine screws are primarily used for a tight part that is tightly threaded, with a fastening connection between a part with a through hole, and do not require a nut mate (this connection is called a screw connection and is also a removable connection; it can also be used with a nut for fastening connections between two parts with through holes). The fastening screws are primarily used to secure the relative position between the two parts. Special-purpose screws such as hanging ring screws are used for lifting parts.

4.       Nut:

With internal threaded holes, the shape is generally shown as a flat hexagonal column, but also in a flat square column or flat cylindrical shape, with bolts, studs or machine screws, used to fasten the two parts, making it a whole.

5.       Self-tapping screw:

Similar to machine screws, but the threadon on the screw is a dedicated self-tapping screw thread. Used to fasten the connection of two thin metal components, making it a whole, the component needs to be made in advance small holes, because the screw has a high hardness, can be directly screwed into the hole of the member, so that the component formed a corresponding internal thread. This form of connection is also a removable connection.

6.       Wood screws:

It is also similar to a machine screw, but the thread on the screw is a dedicated wooden screw thread that can be directly screwed into a wooden member (or part) and is used to secure a metal (or non-metallic) part with a through hole and a wooden member. This connection is also a removable connection.

7.       Washer:

A class of fasteners shaped in the shape of a flat ring. Placing between the support surface of a bolt, screw or nut and the surface of the connecting part plays an important role in increasing the contact surface area of the connected part, reducing the unit area pressure and protecting the surface of the connected part from being damaged;

8.       Ring:

It is installed in a machine, equipment shaft slot, or hole slot, and acts as a way to prevent the movement of parts on the shaft or on the hole.

9.       Pin:

Mainly for part positioning, some can also be used for part connection, fixing parts, transmission of power or locking other fasteners.

10.   Rivets:

A class of fasteners consisting of two parts, the head and the nail rod, for fastening two parts (or components with through holes) that connect them to make it a whole. This form of connection is called rivet connection, or riveting. is connected to the non-removable. Rivets on the part must be destroyed to separate the two parts connected together.

11.   Assembly and connection sub-

A combination of fasteners is a combination of a type of fasteners supplied by a combination of a machine screw (or bolt, self-supply screw) and a flat washer (or spring washer, locking washer) and a type of fasteners that combine a special bolt, nut and washer, such as a steel structure connected to a high-strength large hexagonal bolt.

12.   Welding nails:

An heterogeneous fastener consisting of a nail rod and a nail-free head (or nailless head) that is secured by welding to a part (or member) for reconnection to another part.