The most common screw thread types include self drilling thread, self drilling TEKS, Type A thread, Type B thread, Type AB thread, type F and Type C thread. Today let’s talk about the most widely used Type A and Type B thread screw, and how to choose type A or type B thread screw in your fastener project.

As we know type A and type B thread screw are widely use for in the sheet metal.  The difference between Type A and Type B sheet metal screws lies in their thread patterns and intended applications.

Type A sheet metal screws have a sharp, self-tapping thread that is designed to cut into the material as the screw is driven. These screws are commonly used in thinner metal sheets and have a wider pitch (spacing between threads) compared to Type B screws. They create their own mating threads, which makes them suitable for applications where there are no pre-drilled holes. However, they may require more torque to install compared to Type B screws.

Type B sheet metal screws have a blunt, non-tapping thread that is intended for use with pre-drilled or pre-punched holes in wood, plastic, or metal. These screws are typically used in thicker metal sheets or other materials where a pre-drilled pilot hole is necessary. The thread pattern of Type B screws provides greater holding power as it engages with the pre-drilled hole.

Please pay attention that there are many variations of sheet metal screws available, and the specific designations and applications may vary among manufacturers.