Screws are a common fastener used for the assembly of parts, typically being used for wood, sheet metal, and plastic. Screws are notable for their helical ridge, allowing them to be self-threading as they are driven into a surface and pull materials together. In order to install a screw, one needs a tool that matches the head of the fastener. Screw heads can come in numerous styles, those being chosen for a functional or decorative purpose. In this blog, we will discuss the primary types of screw heads, allowing you to better understand how such fasteners are used.
In general, there are two basic designs for a screw head, those of which are countersunk and non-countersunk types. Non-countersunk heads make up the majority of screws that are found on the market, featuring a design where the head is fully exposed. There are numerous subtypes of non-countersunk heads as well, those of which include domed, binding, button, cheese, fillister, flange, hex, pan, round, socket, low socket, square, and truss head styles.
Domed head screw parts may be considered to be one of the most widely used screw types, generally serving applications where the head of the fastener does not need to be hidden. As such, they may be used for numerous assemblies such as furniture or where they may be decorative. Nevertheless, such screw parts are fully fastened into a surface, capable of being driven until the flat, bottom side of the head meets the material.
Countersunk screw heads, meanwhile, are those that either have their head completely in line with the surface of the material or will only slightly protrude out. With this type of assembly, other objects may be rested atop the assembly without having to worry about the presence of a screw. Countersunk screw heads may also come in a variety of subtypes, those of which consist of flat, oval, and bugle heads.
The flat screw head type is a common countersunk screw, capable of sitting entirely flush with the installation surface so that no part of the head protrudes. This is beneficial for assemblies that are commonly passed by or used, preventing the chance of something catching or snagging on the fastener. For installation, flat screws must be countersunk, meaning that a pilot hold and proper angle needs to be established for the screw to be inserted. With a pre-drilled hole, the correct head angle may be achieved to guarantee no protrusions with correct installation.
Beyond the type of screw head, it is also important to consider the drive style or recess that must be used. The drive style refers to the tool type that is used for installation and removal of screws, matching the recess present on the screw head. Typically, the most common tool types are slotted, Phillips, combination, hex, hex socket, square, Torx, and spanner types.
Phillips and standard screwdrivers are commonly used for numerous screw types, featuring a handle and a shaft, the tip being inserted into the screw for turning. The tip may range in its size and shape to accommodate the recess of the screw, examples being flat blade and cross-shaped types. As the size of the screw and its recess may vary, screw tips of the same shape may also vary in size to accommodate different fasteners. In some cases, the tool may feature the ability to quickly insert and remove different tool tips, allowing for a single handle to be used across numerous screw heads.
Hex keys, also known as Allen keys or Allen wrenches, are the other main tool type, often coming in the form of a small handheld tool that may drive fasteners that feature a hexagonal socket. While coming in a variety of sizes, all tend to feature the same shaped tip that is hexagonal. The tool or handle itself may also vary in shape, some featuring L-shaped designs while others may have a sort of S-shape design. These allow for torque to be provided to a screw assembly in different spaces, ensuring that the tool can be spun in tight areas while providing the user with ample grip for force. As compared to standard Phillips head screws, hex keys are known for having an increased amount of pressure points, allowing them to make gripping, installation, and removal easier.
As there are numerous types of screws and tools available, the choice often comes down to the particular needs of an application, such as whether or not the head can be protruding and how it will be installed. When you determine which screw parts you need for a particular assembly, let the experts at Just Parts Unlimited help you procure all the items you desire with competitive pricing and rapid lead-times. We also expedite all shipping for domestic and international orders with our robust supply chain, ensuring that we meet the time constraints of our customers. Get started today and see how Just Parts Unlimited can help you fulfill all your operational requirements quickly and effortlessly.