Screw Head Names: Your Guide to Identifying Them Easily

In the diverse world of fasteners, screws are a staple in daily construction and DIY projects. Understanding screw head types is crucial as they determine the tools you’ll need and the application they’re designed for. Each screw head is shaped differently with varying cavities and protrusions to accommodate their corresponding screwdrivers or bits. This gives you the ability to apply the necessary torque to install or remove a screw efficiently.

What Are the Different Types of Screw Heads?

Screw type fasteners come in a variety of head styles that serve both functional and decorative purposes. Screw heads are broadly categorized into two types – countersunk and non-countersunk.

Countersunk screw heads have a tapered shape that allows the head to sit flush with or below the surface of the material they are screwed into. Common countersunk head styles include flat, oval, and bugle heads. 

These are used when a flush exterior surface is desired for aesthetics, aerodynamics, weatherproofing, or to avoid having screw heads protrude and catch on objects.

Non-countersunk screw heads do not taper and the head is fully exposed above the surface of the material. Common non-countersunk heads include binding, button, cheese, fillister, flange, hex, pan, round, socket, square and truss. 

These heads protrude to allow grasping by tools or hands for driving the screws. They can also serve decorative purposes with styles like slotted hex or round washer heads.

The choice between countersunk versus non-countersunk heads depends on the functional and aesthetic needs of an application. Understanding the difference allows proper screw selection for a design.

Countersunk Screw Head Styles

When you’re working on a project that requires a neat and flat finish, countersunk screw heads are your go-to. These screws are designed to sit flush with the surface they’re driven into. Here’s a rundown of a few common types of countersunk screw heads that you might encounter:

• Flat Head: This type is the most common countersunk screw. It is designed to sit flush with the surface material after installation. This provides a clean, finished appearance, making them ideal for projects where you want a smooth, flat surface without any protrusion. The slot style here is typically a single, straight line that accommodates a standard flat screwdriver.
• Oval Head: Oval head screws combine the advantages of flat and pan head styles. The head has a slightly rounded top that provides a decorative finish, with the lower part of the head tapered like a flat head for countersinking. The slot typically accommodates a Phillips or slotted screwdriver.
• Bugle Head: Mainly used in drywall, the bugle head allows the screw to sit flush without tearing into the material thanks to its curved neck.

Here’s a quick guide to help you identify each type:

Make sure you have the right tools for installation, as the drive recess (for example, Phillips, Torx, or slot) will vary depending on the screw head type. Your project will look seamless and professional with the appropriate countersunk screw head!

Non-Countersunk Screw Head Styles

When selecting the appropriate screw for your project, you’ll encounter various non-countersunk screw head types designed for different applications. Non-countersunk screw heads do not sit flush with the surface of the material. Instead, they protrude, adding strength or aesthetic value depending on your needs.

Binding Head: Your choice if you require a slightly raised, dome-like profile for both fastening and an attractive finish.

Button Heads: Ideal for when you need a low-profile head that’s not completely flush but offers a tidy look with enough surface area to hold materials in place.

Square Heads: Square screw heads have a square recess that allows for high torque driving without camming out. They provide extra gripping power and are common in high-load applications.

Pan Heads: Pan head screws have a rounded shallow dome top. They provide a low profile while still allowing adequate driving torque.

Domed Heads: Domed head screws have a smooth rounded top that rises higher than pan heads. They can be decorative and provide high driving torque.

Round Heads: Round head screws have a domed circular top. They provide good torque capability and can serve decorative purposes like nickel plated brass round heads.

Hex Heads: Hex screws have six-sided heads that allow driving with wrenches or sockets. They come in finished and industrial styles.

Flange Heads: Flange screws have a flat rim under the head that sits flush against surfaces. This provides better holding power.

Truss Head: Truss screws have an extra-wide low dome head to deliver maximum driving torque and load capacity.

Socket cap: Socket cap screws have a cylindrical head with an internal socket drive recess allowing high torque.

Cheese Head: These offer a cylindrical outer edge with a flat top, suitable for applications where minimal protrusion is necessary.

Fillister Head: You’ll find these useful when you need a higher profile than a cheese head, with the ability to drive deeper for a stronger hold.

Inset these screws appropriately using the matching tools—screwdrivers, bits, or wrenches—to ensure that they perform as expected in securing your materials or components.

Remember, selecting the correct head style is just as important as the material and length of the screw for your project’s success.

What Functions Are Screw Drive Types Intended to Perform?

Screw drive types are engineered for diverse functions, such as preventing tampering, ensuring stability during setup, providing application reliability, and offering high-torque insertion strength. We will delve into the characteristics and advantages of all screw options, enabling you to determine the one that suits your requirements:

• Slotted: The slotted drive has a single slot for insertion of a flat-bladed screwdriver. Slotted screw allows limited torque but is inexpensive to manufacture
• Phillips: The Phillips drive has an x-shaped recess that allows self-centering of the driver. It allows more torque than slotted and reduces camming out
• Phillips tamper-resistant: Phillips tamper-resistant adds a pin in the recess to prevent standard Phillips bits from driving it. It provides security while retaining Phillips drive properties
• Combination: Combination drives incorporate multiple drive systems into one fastener head. This allows a choice of drive tools
• Hex external: External hex screws have a hexagonal head that can be driven by wrenches or sockets
• Hex internal: Internal hex has a hex recess requiring an Allen key to drive
• Hex tamper-resistant: Hex tamper resistant fasteners have a pin inside the recess requiring a special bit
• Square recess: Square drive uses a four-sided recess for high torque without cam out
• Square recess tamper-resistant: Square tamper-resistant builds on square drive for security via a central pin
• Quadrex: Quadrex has a 4-lobed recess that resists cam out extremely effectively
• Pozidriv: The Pozidriv screw drive has an x-shaped recess like Phillips, but with additional contact points for higher torque capability before cam-out occurs. Pozidriv screws have etched lines on the screw head to distinguish them from Phillips screws
• Torx: The Torx or star drive screw head has a six-point star shaped recess that allows high torque transmission without cam-out
• Torx tamper-resistant: Torx tamper-resistant screws have a metal pin inserted in the recess that requires a special bit to drive, preventing standard Torx tools from working
• Torx Plus: Torx Plus is an advanced version of Torx that can handle even higher torque loads before cam-out
• Torx Plus tamper-resistant: Similar to standard Torx tamper-resistant, Torx Plus tamper-resistant incorporates a blocking pin in the recess along with the advanced Torx Plus torque and cam-out benefits
• Tri-wing: The Tri-wing screw drive uses a triangular triple-lobed recess that can handle very high torque loads without cam-out
• Spanner: Spanner screw heads have two small holes on opposite sides allowing high grip with special spanner drivers

Choosing the proper driving recess corresponds with your toolset and project needs and can make your task more manageable and the results more reliable.

Industry Standards and Specifications

In the world of fasteners, screw heads come in various shapes and sizes, each with their own specific standards and specifications. Understanding these will ensure you select the right screw for your project.

International Standards

International standards serve as a guide to ensure uniformity and compatibility in the manufacturing and use of screw heads. ISO (International Organization for Standardization) specifies dimensions and characteristics for a range of screw heads. For example:

• ISO 4017:2014 covers dimensions for hex head screws.
• ISO 4762:2004 specifies details for socket cap heads, often used when a high degree of strength is required.

Trade Specifications

In addition to international standards, various trade organizations set specifications to ensure quality and performance across industries. Some of the key entities include:

• SAE (Society of Automotive Engineers): Provides specifications for fasteners used in the automotive sector, for instance, the SAE J429 standard for automotive bolts which can include hex heads.
• IFI (Industrial Fasteners Institute): Offers comprehensive standards for different types of fasteners, including guidelines for socket and hex products.

Conclusion

In your journey of selecting the right screw head for your project, remember that each type brings its own benefits. Whether you’re working with wood, metal, or plastic, the right screw head ensures a snug fit and efficient force transfer.

• Flat-head and Philips screws are commonly used for most basic applications.
• Pozidriv and Torx screws offer more grip and reduce cam out.
• Square recess heads provide a stable drive but may not be as ubiquitous in every toolbox.

Considering materials and tool availability is just as crucial as understanding the task requirements.

When choosing, it’s wise to have a versatile set of tools to match the variety of available screw heads. Your skillset, matched with the correct hardware, will not only make your work easier but also produce dependable and aesthetically pleasing results. Keep this guide handy, and you’ll be well-equipped to tackle any challenge that comes your way.