As an important mechanical connection element, screws have the following uses:

Mechanical connection: Screws can be mechanically connected by holding two or more parts and adjacent surfaces together. They can also withstand tensile, shear, and axial forces, among other things.

Adjust the mechanical properties: the diameter, length, material, head shape, spiral Angle and tooth spacing of the screws and other parameters can be adjusted according to the need, so as to change the stiffness, strength, self-locking, tightening degree and other physical characteristics to adapt to different mechanical design requirements.

The main materials of screws are as follows:

Carbon steel: Carbon steel is a common screw material that is strong and durable enough to be used in most applications and is cheaper than other materials.

Stainless steel: Stainless steel is a kind of high strength, rust proof, corrosion proof excellent screw material, widely used in Marine, petrochemical, food processing and other fields.

Aluminum alloy: Aluminum alloy screws are widely used in high-speed trains, aircraft and automobiles due to their light weight, high strength, good corrosion resistance and fatigue resistance.

Titanium alloy: Titanium alloy screws are a highly corrosion-resistant material with excellent strength, weight ratio and rigidity. They are suitable for high-tech applications and human implants. Head type: The head type of screws usually includes flat head, half round head, round head, cone and other types. Different head shapes can help achieve different mechanical connections and provide a better look.

In addition to the above materials and uses of screws, there are also the following aspects of supplement:

Coating: Many screws will be coated on the surface, such as chrome plating, galvanizing, hot dip galvanizing, etc., to improve durability, corrosion resistance and aesthetics.

Labeling: Some screws may need labeling to distinguish their type, specifications, and performance parameters, such as size, tooth spacing, torque, etc. This information is usually engraved on the head or body of the screw.

Nuts: Nuts are accessories to screws. They are usually used in conjunction with screws and are used to increase the stability and fastening of joints. Nuts are also available in many different types and materials. Pitch: The pitch is the distance between adjacent threads. The larger the tooth spacing is, the smaller the torque is, but the fastening effect is poor. The smaller the tooth spacing, the greater the torque, but the lower the tensile strength.

Tightening torque: The tightening torque is the value of the torque required to secure the screws. Tightening torque depends on screw specifications, materials, and surface lubrication, and must be accurately calculated or estimated according to specific application requirements.

Preload: Preload is a pressure force applied to the screw in order to ensure that the screw connection is effective and can withstand the required load. By increasing the preload, the connection performance and stability of screws can be improved, and the machine failure caused by natural loosening can be avoided.

Self-locking: The shape of the thread makes the screw itself have a loosening resistance performance, that is, self-locking. In order to increase the self-locking of screws, it is usually surface treatment or installation of gaskets and other measures.

Common types of screws: Common screws include bolts, machine screws, tapping screws, wood screws, round screws, etc. Each screw has different pitch, diameter and length characteristics and can be selected according to different application requirements.

Polychloride: Polychloride (PVC) is a plastic material commonly used in the manufacture of screw casings or gaskets. It has good heat resistance, toughness and corrosion resistance, and is easy to process, suitable for all kinds of environment fastening components.

Spring gaskets: Spring gaskets are usually added to screw connections to provide shock absorption and resistance to loosening while the machine is in operation. Spring gaskets have high elastic modulus, which can effectively maintain preload and prevent cracking.

Anti-loosening agent: Anti-loosening agent is a special lubricant that helps prevent threads from loosening. It usually includes materials such as polyurethane, epoxy or acrylic, and can be selected on demand.

Color coding: In order to easily distinguish different types of screws, many manufacturers will color coding different types of screws. For example, yellow means high-strength bolts, green means stainless steel bolts, and red means self-tapping screws with low fastening force.

In short, screw is one of the essential parts in mechanical engineering, its performance and use mode for the stability and safety of the whole device or machine have a crucial impact.