Self-tapping screws do not refer to a single type of screw. There are many other types of self-tapping screws. Their respective characteristics and applications are different. The following is a brief introduction to two types of screws that are easily confused - self-tapping screws and self-drilling screws.

What is a self-drilling screw?

Self-tapping screws are threaded fasteners that drill out matching female threads in pre-drilled holes in metal or non-metal materials. Self-tapping screws do not require female threaded nuts, and they drill out female threads on the material while screwing in. Triangular thread self-tapping screws, high and low pressure self-tapping screws, etc. are all self-tapping screws.

Drill screws are a type of wood screws. Drill screws are screws with a self-drilling head at the front end of the screw, also called self-drilling screws. According to the different drill tails, they can be divided into: round head screw/cross head/plum blossom, countersunk head (flat head)/screw/cross head/plum blossom, hexagonal washer, round head washer (large flat head), trumpet head, etc.

In fact, the two are still closely related. "Self-drilling screws" must be "self-tapping self-drilling screws", referred to as "self-drilling screws". Because of the drill tail, it is also called "drill tail screws", while self-tapping screws are not necessarily self-tapping self-drilling screws. Usually, the self-tapping screws we are talking about refer to self-tapping screws that require prefabricated holes.

The common points between self-tapping screws and self-drilling screws

The nail body has threads and can self-drill.

The difference between self-tapping screws and self-drilling screws

Self-tapping screws

Self Drilling Screws

1. Difference in usage: Self-tapping screws are used on non-metal or softer metals (such as color steel plates) and other materials with low hardness. They can "drill, squeeze, press, and tap" the corresponding threads on the fixed material with their own threads, so that they can fit closely with each other. Self-drilling screws are mainly used to fix color steel tiles and thin plates in steel structures.

2. Difference in usage: When self-drilling screws are screwed in, the corresponding internal threads are formed by extrusion. No drilling or tapping is required, and the operation can be completed in one go. However, multiple drillings are not recommended, as this may damage the holes or cause thread slippage. When self-drilling screws are used, no auxiliary processing is required, and operations such as drilling, tapping, and tightening can be completed directly on the material in one go, greatly saving installation time.

3. The difference in appearance: Self-tapping screws are generally pointed, coarse-toothed, hard, and have a certain taper, so that they can "self-drill" but cannot drill holes. The head of the drill screw thread has a drill bit that can drill holes.