Both screws and bolts are common fasteners, but they have some differences in shape, use, structure and connection method. Here is a comparison between the two:
1. Shape and structure
- Screw
Threaded part: The thread of the screw is usually full thread, that is, it is threaded from the head to the tail of the screw.
Head: Screws have different head shapes, such as round head, flat head, countersunk head, etc., and different tools (such as screwdrivers) can be selected for installation.
Length: The length of the screw is usually shorter, suitable for lighter fixing needs.
- Bolt
Threaded part: The thread of the bolt is usually partial thread, and the thread only exists in part of the screw. The head and tail are usually smooth.
Head: Bolts usually have a hexagonal head (external hexagon), which is convenient for installation with a wrench.
Length: Bolts are usually longer and suitable for fixings that need to withstand greater tension and pressure.
| Features | Bolts | Screws |
| Head design | Hexagonal head/flange head (ISO 4014) | Cross recess/slotted (ISO 7045) |
| Shape shape | Plain rod section + threaded section (DIN 931) | Full thread or progressive thread (DIN 7981) |
| End treatment | Flat end or chamfer (Ra≤3.2μm) | Self-tapping pointed head (angle 30-45°) |
2. Connection method
- Screws: Screws are often used to fix items directly into materials (for example, wood, plastic, or metal). They do not require nuts and are usually connected directly to the workpiece material through their own threads, or fixed by screwing into a pre-made hole.
Application examples: used in furniture, electronic equipment, and light machinery.
- Bolts: Bolts are usually used with nuts and connected to another piece of material through a hole. Bolts need to be tightened with tools (such as wrenches) to ensure a secure connection. The combination of bolts and nuts can provide higher fixing force.
Application examples: used in higher-strength applications such as mechanical equipment, steel structures, and construction projects.
3. Uses
- Screws: Suitable for lighter loads and fastening tasks, and are often used in small machinery, household appliances, woodworking, and electronic equipment in daily life.
- Bolts: Suitable for high-load connections that require greater strength and durability, and are widely used in industries, construction, bridges, and large machinery.
4. Installation method
- Screws: Usually installed by screwing directly into the material, without the need for additional accessories (such as nuts). Its installation is usually simple and suitable for quick installation.
- Bolts: Bolts are installed through holes and in conjunction with nuts, and usually require a wrench or other tool to tighten. Bolts are usually more complicated to install and remove than screws, but they provide stronger fixing force.
The choice of using screws or bolts depends mainly on the strength requirements of the connection and the working environment.
Post time: Mar-12-2025