Wood screws, also called wood screws, are similar to machine screws, but the thread on the screw is a special wood screw thread, which can be screwed directly into the wooden component (or part) to use a metal (or non- The metal) part is firmly connected to a wooden component. This connection is also a detachable connection.
This is a nail designed specifically for wood. After entering the wood, it will be embedded very firmly. If the wood is not decayed, it is impossible to pull out, even if it is pulled out forcibly, it will bring out the nearby wood.
One more thing to note, wood screws must be screwed in with a screwdriver, and threads are machined on the inner surface of the hole. Wood screws have low strength and can only be used in harder places. The threads of wood screws are deeper than machine screws with the same diameter. The diameter of the commonly used wood screws is about 2.5-4 mm, and there is no matching screw cap. Generally use a flat or cross screwdriver for operation. Generally used for fixed connection such as wood and plastic.
As the name suggests, you can tap the screws yourself. Normal screws must have machined screw holes before they can be screwed in. Self-tapping screws do not need to be tapped while screwing in. Self-tapping screws are stronger and used to tighten harder places.
The shape of the self-tapping screw is similar to that of the wood screw but there are certain differences: the small diameter rib part has an axial groove at the front end, and the larger diameter has a flat drill-like part besides the groove.
Self-tapping screws are often exposed outdoors and have strong corrosion resistance; their rubber sealing ring can ensure that the screw does not seep water and has good corrosion resistance. In order to achieve the purpose of self-tapping, this kind of screw is generally pointed to facilitate squeezing into the object to be screwed.
Self-tapping screws are generally operated manually. Due to manpower constraints, these screws are generally small and have a relatively narrow range of use.
Self-tapping screws have high hardness, wide thread spacing and deep threads, and the surface is not smooth. Wood screws are the opposite. Another difference is more obvious, the wood screw has no thread in the rear section. Wood screws are thin, blunt and soft. Self-tapping screws have thick threads, sharp and hard.