Machine screws, also called machine bolts, are the fasteners that average consumers typically think of when they need a screw. They’re uniformly-threaded screws of ¼ inch nominal diameter or less that are designed to be threaded into likewise uniformly-threaded nuts or threaded holes in the components being fastened. Machine screws are generally available in a wide array of configurations, materials, driver head types and sizes.
Machine screws have characteristics that include:
- Two major types of heads — slotted and Phillips – although unique head configurations, such as star-shaped Torx heads, are also available for specialized applications
- Uniform threads that maintain the same diameter throughout the threaded section length, unlike the tapered threads of wood screws
- A variety of materials from which they are manufactured, including steel, stainless steel, brass, and nylon
The choice of which type head to use for a specific application is determined by the finished appearance required. Round and pan heads protrude above the surface when installed and allow for washers that can help secure them. Flat head machine screws are used in applications requiring a flush surface upon installation and allow for a snag-free or snug fit when the assembled component comes in contact with another surface.
Thread characteristics, including diameter and pitch, are an important design element in machine screws because the corresponding holes that they are fastened to typically will be tapped to fit only one specific size and type of thread. For added versatility, machine screw threads can be designed to screw in clockwise or counterclockwise, depending on use.
To learn more about machine screws or to discuss the most appropriate configuration for your application, contact the machine screw specialists here at Electronic Fasteners.