Shuanne, a lot of engineers get confused between self-tapping and self-drilling screws. They are different.

TLDR; both self-tapping and self-drilling screws can tap their own threads, but self-drilling screws can also drill their own holes.

Let's discuss a bit in more detail.

Self-Tapping Screws:

Self-tapping screws are designed to tap their own threads as they're driven into material.

These screws don't require a pre-drilled hole, but you might still need to make a pilot hole in denser materials to guide the screw correctly and prevent the material from splitting.

Self-tapping screws are usually used for connecting thin or soft materials, like wood or plastic, or for attaching things to metal.

There are two main types of self-tapping screws: thread-forming and thread-cutting. Thread-forming screws are usually used in plastic, as they create a very tight fit but can damage harder materials.

On the other hand, thread-cutting screws have a sharp cutting edge that forms a groove in the material. They're used in metal and harder materials, as they remove some of the material to form the thread.

Self-Drilling Screws:

Self-drilling screws, also known as Tek screws, are a type of self-tapping screw that also includes a drill bit tip. The drill bit tip is designed to drill its own hole before the threads start to cut into the material. They're great for saving time in installation, as they combine the drilling and fastening steps into one.

Self-drilling screws are primarily used for attaching thin metal sheets together or to wood. They're often used in the construction and HVAC industries, for instance, in situations where fast and efficient assembly is needed.

Hello Rohit, thank you for the valuable insights! Have a great day :)