Self-tapping screws and self-drilling screws are two of the most common types of fasteners. Both types of screws are heavily used in general construction, especially when it comes to metal fastening.

The primary difference between self-tapping and self-drilling screws is the pilot hole.

Self-Drilling Screws >>
Self-drilling screws are easily distinguished by their drill-bit-shaped tip. They’re often called Tek® Screws after the brand that made the screw a household name.

The drill-bit tip of a self-drilling screw allows the screw to be used without a pilot hole, allowing the user to save time. It may not seem like much, but if many screws need to be used, drilling every pilot hole can eat up a considerable amount of time.

Self-drilling screws are capable of fastening alike materials, such as metal to metal, or two different materials, such as metal to wood. They’re typically used in lighter gauge applications. However, a #5 drill point self-drilling screw is capable of fastening heavier-duty materials, such as a half-inch steel sheet.

Self-Tapping Screws >>
Self-tapping screws are also known as metal screws, sheet metal screws, or tapper screws.

Self-tapping screws cannot be used without a pilot hole being drilled beforehand. As the name suggests, a self-tapping screw can tap threads into the material being used. The tapping action is an extra layer of protection to ensure the materials remain fastened together.

One of the most important aspects of using self-tapping screws correctly is the hole size. If the pilot hole is too big, the screw won’t fasten properly, won’t create an effective thread, and can’t secure the material. If the hole is too small, a self-tapping screw can actually split or crack the material.

Self-tapping screws work well in several applications, from metals to plastics and even some forged materials, such as aluminum or iron.

Self-Drilling Screws VS Self-Tapping Screws