Self-Drilling vs. Self-Tapping Screws

Self-Drilling vs. Self-Tapping Screws

When it comes to screws, there is often confusion between Self-Drilling and Self-Tapping screws. It’s important to understand the differences between these two types of screws as they have different properties and applications.

Despite the fact that they have some similarities, there are also some distinct differences between them. However, many people often have difficulty understanding the differences between these two types of screws.

Image: BDN Fastener

We have noticed that people usually asking for self-drilling screws at shops actually need self-tapping one type.

Read more: Top 22 types of Screws used in the world.

Self-Drilling Screws

Self-drilling screws are designed with a drill point at their tip, which allows them to easily drill into metal without pre-drilling or tapping. These screws are designed to create a hole in the target material as they are driven, eliminating the need for pre-drilled holes.

The design of self-drilling screws typically consists of an unthreaded shank topped by either a countersunk or pan head, along with flutes & drill points that allow the screw to be driven into the material without pre-drilling.

The main parts of a self-drilling screw are the head, threads, wings, flute, pilot section, and drill point as shown in the below figure.

The threads on self-drilling screws are designed to cut through metal quickly, providing secure fastening with minimal effort. Self-drilling screws also feature sharp drill points that help guide them through the material being drilled.

These screws are primarily used when attaching materials such as sheet metal together, or when fastening materials together in difficult areas where a traditional drill isn’t practical. They are also ideal for quickly fastening large amounts of material together due to their ability to be driven very quickly.

Self-Tapping Screws

The design of self-tapping screws consists of a pointed tip that allows the screw to penetrate the material, forming internal threads once it has been installed.

The cutting edge on the tip creates small chips in the material as it moves forward and is followed by multiple cutting flutes which aid in clearing away debris created by drilling into a surface.

Self-tapping screws are an essential item in any toolbox and are widely used in both home improvement and industrial projects.

These straight-shank fasteners can be easily driven into a variety of substrates without the need for pre-drilling or tapping. Self-tapping screws provide a tight and secure fit that is hard to achieve with other types of fasteners.

Read more: Types of Bolt Heads.

The most common type of self-tapping screw is the sheet metal screw – these have sharp cutting threads designed to drive through thin sheet metal items such as ducts or electrical boxes.

There are also wood screws specifically for woodworking projects which feature a deep thread pattern for better gripping power in softwood or plywood applications.

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