Flat Head Screw Guide: Everything You Need To Know

Flat-head screws are a type of fastener with a flat or horizontal drive head. They are cone-shaped or countersunk, meaning they can be aligned flush or below the surface of the material into which they are being driven. Flat-head screws are useful for finish work, as they can be hidden with a screw cover, also known as a beauty cap. They are also easier to clean out in dirty environments. Flat-head screws come in a variety of sizes, with different angles of countersink, and can be slotted or Phillips.

Flat head screw sizes

Flat-head screws, or bolts, are a type of fastener with a flat or horizontal drive head. They are often used in machinery, electronics, and equipment assembly.

The size of a flat-head screw is determined by a combination of factors, including the basic screw diameter, protrusion above the gaging diameter, and the recess penetration gaging depth. The size of the driver required to turn the screw is also an important consideration. Flat-head screws typically have either a slot or Phillips drive feature. The Phillips drive is x-shaped and requires a Phillips screwdriver for installation.

Flat-head screws come in a range of sizes, with the #10-24 size being commonly used in machinery, electronics, and equipment assembly. This size of screw has a thread size of 24 TPI (coarse standard thread) and a Phillips #2 drive type. The length of flat-head screws can vary, and they are typically measured from the top of the head to the tip.

In addition to the standard measurements, flat-head screws also have specific dimensions for the head design. The head of a flat-head screw is countersunk, meaning it has a cone-shaped design under the head with a flat top. This allows the screw to sit flush with the surface when installed, resulting in a clean and professional appearance.

Flat head screw specifications

Flat-head screws are a type of fastener with a flat or horizontal drive head that can be slotted or fitted with a Phillips drive feature. They are designed to sit flush with the surface when installed, providing a clean and professional look. The flat head is also advantageous in dirty environments as it is easier to clean out.

Flat-head screws are available in a range of sizes and can be made from stainless steel, making them corrosion-resistant and ideal for both indoor and outdoor use. The standard thread size for flat-head screws is 32 TPI (coarse/standard thread), and they are available in various lengths. The length is measured from the top of the head to the tip.

The head of a flat-head screw can be cone-shaped or countersunk, with the angle of the countersink usually being 82 degrees for UNC and UNF applications. However, other angles ranging from 60 to 120 degrees can also be specified.

Flat-head screws typically follow the following specifications: ASME B18.3, ASME B18.3.6, DIN 963 / ISO 2009, DIN 965 / ISO 7046, and DIN 7991 / ISO 10642. The size of flat-head screws can vary, with the smallest being #00-4" and the largest M1.2-M100.

Flat head screw driver availability

Flat-head screwdrivers, also known as slotted screwdrivers, are widely available from numerous retailers. They are a common type of screwdriver and can be purchased from hardware stores, home improvement stores, and online marketplaces.

When choosing a flat-head screwdriver, it is important to consider the size and type of screw you will be working with. Flat-head screwdrivers come in various sizes, from small precision screwdrivers for electronics to larger ones for construction projects. The length of the shaft and the width of the flat tip need to be taken into account to ensure a proper fit.

Some flat-head screwdrivers have magnetic tips, which can help with holding screws in place during use. Additionally, the handle material is an important consideration. Soft, padded handles provide comfort and reduce hand strain for extended periods of work, while hard plastic grips offer improved control and driving power for smaller tasks.

Some popular brands offering flat-head screwdrivers include Craftsman, Klein Tools, Stanley, Husky, Milwaukee, and Edward Tools. These screwdrivers can be purchased individually or as part of a set, which often includes various sizes and types of screwdrivers to handle different tasks.

Online retailers such as Amazon offer a vast selection of flat-head screwdrivers, with thousands of options available. The Home Depot also provides a range of flat-head screwdrivers in different sizes and styles, including standard, heavy-duty, and precision options.

When purchasing a flat-head screwdriver, it is important to ensure that it is made of durable material, such as stainless steel, to prevent corrosion and ensure longevity. Proper care and maintenance, including keeping the screwdriver clean and dry, will also help extend its lifespan.

Flat head screw advantages

Flat-head screws have been used for centuries, initially for cabinetry work and to secure plates on jousting armour. They are still widely used today, especially in woodworking and general home repair projects.

One of the main advantages of flat-head screws is their compatibility with a range of tools. Flat-head screws can be used with both straight-edged and Phillips screwdrivers, and some even come with specially designed heads to accommodate both. This versatility means that flat-head screws can be easily tightened or loosened with a variety of tools, including coins, knives, and other non-screwdriver implements.

In woodworking, flat-head screws are essential. Woodworkers use them almost exclusively to hold together cabinets, bookcases, stair threads, tables, and benches. The flat head allows the screw to be covered with wood putty, sanded down, and coated with a wood finish, creating a seamless and aesthetically pleasing result.

Additionally, flat-head screws are advantageous in preventing over-tightening and stripping. Their design makes it easier to “feel” for proper set when tightening by hand, reducing the risk of applying excessive torque and damaging the screw head or the material it is fastened to.

Flat-head screws are also useful in certain manufacturing processes. They are often used in hanging drywall, mounting door hinges, cabinets, and installing tabletops. The flat head allows for a smooth and flush finish, ensuring that the screw does not protrude or interfere with the functionality of the finished product.

While some newer types of screws, such as Phillips and Robertson, offer their own benefits, flat-head screws remain a reliable and versatile option for many applications, especially in woodworking and construction.

Flat head screw alternatives

Flat-head screws are a type of countersunk screw, meaning they sit flush with a surface, leaving no part of the head exposed. This makes them ideal for applications where a smooth surface is required, or where there is a risk of objects catching on a raised screw head.

There are several alternatives to flat-head screws, depending on the specific application and requirements. Here are some options:

Raised Head Screws

Also known as oval-shaped head screws, these have a similar angle to flat-head screws but feature a domed head. They require a countersink to accommodate the angle, and the head will protrude slightly from the surface. This shape does not improve the drive performance of the screw.

Bugle Head Screws

Bugle head screws are commonly used for drywall and plasterboard. They are similar in shape to flat-head screws but feature an angle under the surface of the head, which helps to reduce damage to the surface. They are self-drilling, so pilot holes are not required. The unique shape of bugle head screws distributes stress over a wider area compared to flat-head screws.

Binding Head Screws

These screws are unique and can be used for a variety of projects. They have domed heads and can screw into each other. Short binding screws are often used for holding large manuals or bookbinding projects, as well as for leatherwork.

Dome Head Screws

Dome head screws are a common type of screw. They are suitable for work where the head of the screw does not need to be hidden. The dome shape provides an appealing design, and the flat part behind the dome helps to stop the screw at the desired depth.

Flange Head Screws

Also known as frame screws, flange head screws have a head that can be circular or hexagonal. They feature a circular flange directly below the head, which extends outward. The flange provides stability and acts as a washer to keep the screw in position.

Truss Head Screws

Truss head screws are wider than standard screws and have a rounded surface. They are often used for sheet metal work or projects that require large holes. The wider head prevents the screw from falling into the hole.

Button Head Screws

Button head screws have a rounded head and are commonly used in socket-driven screws. They are becoming more common with Torx or six-lobe drives. Button head screws are ideal for light-duty applications such as removable panels and security installations.

Hex Head Screws

Hex head screws, also known as hex bolts, are bolt fasteners with a six-sided hexagonal head and an externally threaded body. They allow for greater torque than traditional screws with a circular head. Hex head screws are typically used with a washer and hex nut assembly or a tapped hole.

Frequently asked questions