What is the difference between bolts and screws

Screws and bolts are two common types of fasteners that differ in structure, purpose, and other aspects.

1、 In terms of structure

1. Bolt

A bolt usually consists of a head and a screw (a cylindrical body with external threads). There are various shapes of the head, commonly including hexagonal head, round head, etc. The head of a hexagonal bolt is hexagonal, which makes it easy to use tools such as wrenches for tightening and loosening operations. For example, in mechanical assembly, hexagonal bolts can be precisely torqued with a wrench to ensure a tight fit with the nut.

The length and diameter of the screw part vary according to different specifications. The screw of a bolt is usually a combination of a bare rod (without threads) and a threaded part. The light rod part is mainly used to facilitate the bolt to pass through the hole of the connected part during installation, while the threaded part is used to fit with the nut.

2. Screws

The structure of screws is relatively simple, usually including a head and a screw. The head shapes of screws are also quite diverse, such as cross groove heads (cross screws), straight groove heads (straight screws), etc. These head shapes are mainly designed to accommodate different screwdrivers for operation.

The screw part of a screw usually has threads starting from the head, and the threads usually extend to the end of the screw. For example, the thread of a wood screw is tapered, which allows the screw to better self tap when screwed into wood, gradually penetrating into the interior of the wood and serving as a fixation.

2、 In terms of usage

1. Bolt

Bolts are mainly used to connect two or more parts and usually need to be used in conjunction with nuts. It has a wide range of applications in various fields such as construction, machinery, and automobiles. In the field of architecture, bolts are used to connect steel structural components such as steel beams and columns. By threading bolts through holes in steel beams and columns, and then tightening nuts, they can be firmly connected together to form a stable structure.

In mechanical manufacturing, bolts are used to secure various components of a machine. For example, in the assembly process of the engine, cylinder head bolts are used to tightly fix the cylinder head to the engine block, ensuring the sealing and normal operation of the engine.

2. Screws

The application range of screws is also very wide, but their usage is different from that of bolts. Screws can be used alone or in combination with nuts. For example, self tapping screws are commonly used to connect metal sheets, plastic products, etc. Cross screws are widely used in the assembly of electronic product casings. These screws can be directly screwed into pre machined holes to secure different components together.

In the field of woodworking, wood screws are used to connect wooden components. The tapered thread design of wood screws allows them to adapt well to the texture of wood, automatically tapping when screwing in wood, tightly connecting wood components together, and used for making furniture and other wooden products.

3、 In terms of strength and performance

1. Bolt

Generally speaking, the strength of bolts is relatively high. This is because the design and manufacturing process of bolts focus on their ability to withstand large tensile and shear forces. High strength bolts are widely used in the fields of machinery and construction, as they can withstand large loads. For example, in the steel cable connection part of a bridge, highstrength bolts are used to ensure a firm connection between the steel cable and the bridge structure, and to withstand the enormous tensile force generated by loads such as vehicles.

2. Screws

The strength of screws varies depending on their type and material. Some small screws, such as plastic screws used in electronic devices, have relatively low strength and are mainly used for connecting lightweight materials. And some screws made of special materials, such as stainless steel screws, have good corrosion resistance and certain strength, and can be used in some environmentally demanding situations, such as outdoor equipment connections.