Self-Tapping Screws vs. Type 17: Which One Should You Use?

If you’ve ever stood in the fastener aisle wondering whether to grab self-tapping screws or Type 17 screws, you’re not alone. Many assume they are interchangeable, but they serve distinctly different purposes—and choosing the wrong one can lead to stripped holes, split timber, or unnecessary pre-drilling.

What is a self-tapping screw?

A self-tapping screw creates its own threads as it is driven into a material, eliminating the need for a separate tapping operation. However, most standard self-tapping screws still require a pilot hole to be drilled beforehand, especially when fastening into metal or hard plastics. They work by either forming (displacing) or cutting (removing) material to produce a tight, secure thread fit. These screws are ideal for metal-to-metal, metal-to-wood, and general assembly where pre-drilling is already part of the workflow.

What makes Type 17 different?

Type 17 is not a separate screw type—it is a specific point style. The defining feature is a milled flute or cutting notch at the tip, similar to an auger bit. This flute actively removes wood chips as the screw drives in, clearing a path and significantly reducing driving resistance. As a result, Type 17 screws can be driven directly into timber without any pre-drilling, even in dense hardwoods, knots, or engineered panels like MDF and particleboard. They also reduce the risk of splitting and allow for faster installation. In fact, Type 17 is the preferred choice for structural timber framing and decking applications in many regions.

When to use each:

Choose standard self-tapping screws when you are working with thin sheet metal, aluminium, plastics, or pre-drilled timber. They are cost-effective and reliable for general fabrication. Choose Type 17 screws whenever you are fastening solid wood, plywood, or composite boards—especially if you want to skip pre-drilling, speed up production, and protect the material from cracking.

In short: all Type 17 screws are self-tapping, but not all self-tapping screws are Type 17. The right choice depends entirely on your material. For metal and pre-drilled holes, stick with standard self-tapping. For wood and timber applications, Type 17 gives you faster, cleaner, and safer driving. Know your point, and you’ll never second-guess your fastener again.