Science Popularization -Different types of screws

Release Time:

Jun 27,2025

Science Popularization -Different types of screws

1. Wooden screws： the most common type of screw， smooth stems and conical tips, making them perfect for penetrating wood.
2. Machine screws. Blunt head screw, threaded, usually made of brass or steel.: to fasten metal parts together
3. Thread cutting mechanical screws. They look similar to standard mechanical screws, but thread cutting mechanical screws are self tapping screws that can create threads in existing holes on metal. Their use: most commonly used for wood and metal.
4. Sheet metal screws are fully threaded and pointed. Their purpose: sheet metal
5. Self drilling screws. A pointed screw with sharp cutting threads that can be tapped during installation. Its purpose: to quickly drill into metal or wood.
6. Hexagonal bolts have flat hexagonal heads and threads, which can be used with nuts or threaded holes.
Their purpose: to fix wood to wood or metal to wood.
7. Carriage bolts. Its features are a smooth circular head and square neck. Its purpose: to fix metal to metal or metal to wood together.
8. Square head bolts have hexagonal heads with wooden threads and sharp tips. They are particularly sturdy fasteners. Their purpose: to connect heavy-duty wood or other heavy materials that bear heavy loads.
9. Hexagonal socket screw. Hexagonal socket screws are commonly referred to as Allen heads because they are secured with a hex Allen wrench and have a hexagonal bore built into the head of the socket. Their purpose: to fix machine parts.
The characteristic of a set screw is that it does not have a screw head. The entire screw can be screwed into the threaded hole, so that the entire screw is not visible. Their purpose: to fix one object inside another object.
11. The eyebolt has mechanical threads and a circular ring at the head end. Its purpose: to secure ropes, chains, or cables.
12. The lifting ring looks similar to the lifting ring bolt, but uses wood threads instead of machine threads.
Its use: Lightweight application of wood or lagging anchors.
The head end of the J-bolt has a "J" - shaped hook.
Usage: Used as a fastener for construction projects.
14. U-bolts. U-bolt is a type of U-shaped fastener. The U-bolt has two threaded arms extending from the curved base. Its purpose: to fix pipelines and serve as anchoring devices for foundations and roofs.
15. Shoulder bolt. Shoulder bolt, also known as discharge bolt, has a circular head and a machine made tip. Usage: Rotating objects such as bearings and bushings.
The characteristic of elevator bolts is that the head is large and flat, and the bolt length is long. Its purpose: used in conveyor belts, elevators, and similar mechanical systems to lift and lower objects