Standard machine screws go into tapped holes with premade threads. But some assemblies benefit more from thread-forming screws—screws that bite into untapped holes and create their own threads. These fasteners have the same standard thread pitch and size options as machine screws, but their sharp points and hard threads can carve through untapped holes for a tight, long-lasting hold.
Learn more about the advantages of replacing everyday machine screws with thread-forming screws in your next project.
What Is a Thread-Forming Screw?
Everyday screws and thread-forming screws both serve the same primary function: they hold assemblies together by fastening through holes in two or more components. But how they perform this function is different.
Everyday machine screws fasten components with pre-threaded holes. Thus, these screws have slightly softer threads and a blunted point. They also generally require a locking element, such as a nut.
Thread-forming screws don’t need a locking element or pre-drilled threads in the mating hole. Instead, each thread-forming screw has a sharp point and hardened threads. As users insert the thread-forming screw, the threads cut into the material and lock the fastener into place. Thread-forming screws can form threads in many different kinds of materials, including non-ferrous metals and malleable steel alloys.
The key advantages of using thread-forming screws instead of everyday screws are:
- Tight Self-Locking Capabilities: Thread-forming screws make their own threads without leaving gaps between the male and female threads. With everyday machine screws, these gaps can lead to rotational loosening over time. Thread-forming screws also eliminate the need for additional locking components like nuts.
- No Removal of Chips: Thread-forming screws do not produce chips that must be removed. Rather, the material is displaced within the mating component, strengthening the joined parts.
- Reduction of Fasteners: In addition to eliminating additional locking elements, thread-forming screws form tighter bonds and can reduce the total number of fasteners needed in an assembly. Better structural integrity of fasteners leads to further cost savings and reduced weight.
- Simplicity of Construction: Manufacturers don’t need to tap holes, worry about thread tolerances, or inspect the screw threads.
What Are Thread-Forming Screws Used For?
Choosing the right fasteners makes your products and assemblies better. Manufacturers can simplify and speed up production by choosing thread-forming screws for virtually all assemblies made of softer materials, especially where cutting threads could weaken the material. Common applications of thread-forming screws include:
- Composites: Thread-forming screws can create a secure connection between composite materials without degrading local material properties.
- Plastics: By eliminating the tapping stage, manufacturers minimize the risk of breakage and cracking, which can weaken the assembly and lead to product failure. Manufacturers commonly use thread-forming screws for plastic assemblies like automotive components, electronic enclosures, medical equipment, and safety devices like carbon monoxide detectors.
- Sheet Metal: Thin sheet metal is typically incompatible with pre-drilling processes. Instead, technicians can tightly fasten together sheet metal assemblies like HVAC ducts with small thread-forming screws that lock into place with a single turn.
Contact Associated Fastening Products
Associated Fastening Products is a trusted provider of thread-forming screws for manufacturing, on-site assembly, and construction projects. For over 35 years, our organization has served OEMs across all major markets with dozens of different fasteners, bolts, washers, brass fittings, and other components. Through our network of distribution centers across the United States, we can fulfill your fastener orders with short lead times.
Contact us today to learn more about our extensive inventory of fastener solutions, or request a quote to place your order.