Self Drilling Screws vs Self Tapping Screws

It can be tough to find the right screw when a store has hundreds of different screws in stock.

Having to search for hours can be draining, and brands often advertise their products as the “best” or “industry standard”.

There are often many questions when trying to figure out what screws are required as fasteners for a DIY project or construction job.

What materials can they be used for? Is there anything you need to prepare? What’s the difference between the different screws?

Self-drilling screws and self-tapping screws sound like they might be similar, and are both used as fasteners, but there are a few key differences.

The different categories of screws can cause confusion, but we’ll dive into the differences in type and benefits of self-tapping and self-drilling screws below.

Self-Drilling vs Self-Tapping: What’s the Difference?

Confusingly, all self-drilling screws are self-tapping. The two types of screws are used in a number of construction situations.

The material of screws is often stainless steel, but this can vary depending on the screw’s purpose.

Despite this similarity between the types of screws, self-tapping and self-drilling screws come with a few key differences.

The key difference in the type of screw is the lack of a drill point at the tip of a self-tapping screw, saving the need for drilling a pilot hole before starting to thread.

A self-tapping screw cannot punch through thick metal, due to its lack of drill point, and are generally used in woodworking and sheet metal work.

Self-drilling screws are often used in heavy metalwork due to their drilling abilities, thanks to the tip of the screw and ability to thread.

Let’s dive into the main characteristics.

What is a Self-Tapping Screw?

Named for their ability to independently tap threads when screwed into a pre-drilled hole, self-tapping screws have cutting threads that mean they create a strong, durable connection with the drilling material.

Self-tapping screws do require a pilot hole during installation, and the main tip is that the hole size must be slightly smaller than the self-tap screw size, meaning the exact drill size is extremely important.

This ensures the thread connection between the screw and material is strong.

The wrong size drill will mean the pilot holes are the wrong size, causing a loose connection between screw and drilling material.

Self tappers also remove the need for a screw tap. Taps are cutting tools designed to thread material prior to inserting the screw.

Self-tapping screws save assembly time and resources by threading a pilot hole with its sharp cutting threads instead of requiring prior threading.

Self-tapping screws come in many shapes, materials and sizes, and vary depending on the material being drilled into.

Self-tapping screws can also be known as P-K screws, after Parker-Kalon®, the company that pioneered the first self-tapping screw, so keep an eye out for them!

What Are Self-Drilling Screws?

Also known as Tek Screws, the brand name that is the standard, self-drilling screws work best in both wood and metal-working situations.

Drill points are the main difference between self-drilling screws and self-tapping screws.

Wearing out drill components is taken out of the equation thanks to the screw’s ability to drill a hole as well as use its sharp cutting threads to create a strong connection in a single operation.

The need for an initial pilot hole is void thanks to a thread-cutting screw, and these screws often the fasteners of choice in metal to metal, wood to wood, and wood to metal construction.

A thread-cutting screw is perfect for soft material with its twist drill shaped point, and will create a firm connection with its sharp threads and its threading-like action.

What Are the Benefits of Using a Self-Drilling Screw?

The main advantages of a self-drilling screw include the speed of installation and less wear on expensive drill bits, avoiding the need for additional purchases when others break.

Additional drill bits are expensive, and while a drill bit might last for a long time in normal circumstances, doubling its use to drill pilot holes for screws can take its toll. Using a self-drilling screw means this is a much smaller issue.

Thanks to self-drilling screws, one less phase of drilling a substrate, often making it a one step process, means installation time is massively reduced, and drill bits stay in better condition for longer. It’s a win-win!

What Are the Benefits of Using a Self-Tapping Screw?

A self-tapping screw is able to create a strong, firm connection in most materials. Self-tapping screws make great fasteners for sheet metal.

The best part of self-tappers is the large number of situations they can be used in. A pilot hole doesn’t always have to be drilled, they can also be punched into materials like sheet metal and plastic, making the use of self tappers faster than if a pilot hole was drilled.

Self-tapping screws can also be known as a sheet metal screw, thanks to their extensive use in sheet metal construction.

Metal sheets often throw up metal filings and wood drilling will throw up wood chips though, so make sure to wear goggles!

Regardless of the fastener products chosen, the fastening process is much faster with both self-tapping and self-drilling screws.

Whether the fastener chosen is a self-tapping or self-drilling screw, the different types of screws are often interchangeable but all have stronger and weaker areas. They won’t be able to replace structural screws though.

They’re both time saving and as long as all of the tips and instructions are followed, you’re on your way to being a DIY pro.