Understanding Allen Head Countersunk Screw Dimensions And Their Applications

Allen head countersunk screws are bolts designed to fit inside a countersunk hole. They are used in applications that require a visually pleasing fastener with minimal load-bearing capabilities. These screws are not intended for high-strength applications. The head of a countersunk screw is designed to sit neatly on the surface, allowing for smooth construction. They are available in various materials, such as stainless steel, carbon steel, and alloy steel, and can be used in wooden, metallic, marine, and domestic applications. The dimensions of countersunk Allen head screws vary, with specific sizes available to suit different applications.

Allen head countersunk screw dimensions in metric

Allen head countersunk screws are available in a variety of materials, including stainless steel, carbon steel, alloy steel, and zinc. They are commonly used in applications where a visually pleasing fastener is required and are not intended for high-strength applications. The dimensions of Allen head countersunk screws in metric are standardised under DIN 7991, ASME B18.3, and ASME B18.6.3.

The dimensions of Allen head countersunk screws in metric vary depending on the size of the screw, which is designated by the letter "M" followed by a number indicating the nominal diameter in millimetres. For example, an M3 screw has a nominal diameter of 3 millimetres. The length of the screw is usually specified in millimetres as well, such as 10mm or 20mm.

The diameter of the Allen key required to tighten or loosen the screw is also an important dimension to consider. This dimension is typically specified in millimetres as well. For instance, an M3 screw with a 2mm Allen key drive is commonly available.

In addition to the screw length and Allen key size, the thread pitch is another critical dimension for Allen head countersunk screws. The thread pitch refers to the distance between each thread on the screw and is typically specified in millimetres as well. A finer thread pitch will have a smaller distance between threads, while a coarser pitch will have a larger distance.

When installing Allen head countersunk screws, it is important to ensure that the countersunk hole is the correct size. The countersunk hole is the tapered hole that allows the head of the screw to sit flush with the surface of the material. The dimensions of the countersunk hole, including the pilot hole diameter and countersink diameter, will depend on the size of the screw and the fit required.

Allen head countersunk screw dimensions in imperial

Imperial Allen head countersunk screw dimensions are given in either inches or the equivalent metric measurements. The standard thread type for imperial measurements is Unified National Coarse (UNC), which has fewer threads per axial distance than Unified National Fine (UNF).

The length of the screw is given by the second measurement, excluding the words 'Flat Head' and 'Socket Cap Screw UNC'. For example, in the product 'FHSC 6-32 x 1-1/4 UNC', the length is 1-1/4 inches.

The diameter of the screw is given by the first measurement, excluding the words 'Flat Head' and 'Socket Cap Screw UNC'. For example, in the product 'FHSC 6-32 x 1-1/4 UNC', the diameter is 6-32.

The following are examples of imperial Allen head countersunk screw dimensions:

• 1/4-20 x 1 inch
• 1/4-20 x 3/8 inch
• 1/4-20 x 1/2 inch
• 1/4-20 x 5/8 inch
• 1/4-20 x 3/4 inch
• 1/4-20 x 1-1/4 inch
• 5/16-18 x 1/2 inch
• 5/16-18 x 5/8 inch
• 5/16-18 x 3/4 inch
• 5/16-18 x 1 inch
• 5/16-18 x 1-1/4 inch
• 5/16-18 x 1-1/2 inch
• 5/16-18 x 1-3/4 inch
• 5/16-18 x 2 inch
• 5/16-18 x 2-1/4 inch
• 5/16-18 x 2-1/2 inch
• 5/16-18 x 3 inch
• 5/16-18 x 3-1/2 inch
• 5/16-18 x 4 inch
• 5/16-18 x 4-1/2 inch
• 5/16-18 x 5 inch
• 5/16-18 x 6 inch
• 3/8-16 x 3/8 inch
• 3/8-16 x 1/2 inch
• 3/8-16 x 5/8 inch
• 3/8-16 x 3/4 inch
• 3/8-16 x 1-1/4 inch
• 3/8-16 x 1-1/2 inch
• 3/8-16 x 1-3/4 inch
• 3/8-16 x 2-1/4 inch
• 3/8-16 x 2-1/2 inch
• 3/8-16 x 2-3/4 inch
• 3/8-16 x 3-1/2 inch
• 3/8-16 x 4-1/2 inch
• 7/16-14 x 3/4 inch
• 7/16-14 x 1 inch
• 7/16-14 x 1-1/4 inch
• 7/16-14 x 1-1/2 inch
• 7/16-14 x 1-3/4 inch
• 7/16-14 x 2 inch
• 7/16-14 x 2-1/2 inch
• 7/16-14 x 3 inch
• 7/16-14 x 3-1/2 inch
• 7/16-14 x 4 inch
• 1/2-13 x 1/2 inch
• 1/2-13 x 5/8 inch
• 1/2-13 x 3/4 inch
• 1/2-13 x 7/8 inch
• 1/2-13 x 1-1/4 inch
• 1/2-13 x 1-1/2 inch
• 1/2-13 x 1-3/4 inch
• 1/2-13 x 2-1/4 inch
• 1/2-13 x 2-1/2 inch
• 1/2-13 x 3-1/4 inch
• 1/2-13 x 3-1/2 inch
• 1/2-13 x 4-1/2 inch
• 1/2-13 x 5-1/2 inch
• 5/8-11 x 3/4 inch
• 5/8-11 x 1-1/4 inch
• 5/8-11 x 1-1/2 inch
• 5/8-11 x 1-3/4 inch
• 5/8-11 x 2-1/4 inch
• 5/8-11 x 2-1/2 inch
• 5/8-11 x 2-3/4 inch
• 5/8-11 x 3-1/2 inch
• 5/8-11 x 4-1/2 inch
• 3/4-10 x 1-1/4 inch
• 3/4-10 x 1-1/2 inch
• 3/4-10 x 1-3/4 inch
• 3/4-10 x 2-1/4 inch
• 3/4-10 x 2-1/2 inch
• 3/4-10 x 2-3/4 inch
• 3/4-10 x 3-1/4 inch
• 3/4-10 x 3-1/2 inch
• 3/4-10 x 4-1/2 inch
• 3/4-10 x 5-1/2 inch
• 3/4-10 x 10 inch

Allen head countersunk screw materials

Allen head countersunk screws are available in a variety of materials, each with its own unique properties and applications. Here is an overview of the commonly used materials for Allen head countersunk screws:

Stainless Steel

Stainless steel is a popular choice for Allen head countersunk screws due to its strength, corrosion resistance, and durability. It is often used in applications where corrosion resistance is important, such as marine, wooden, and metallic environments. Stainless steel Allen head countersunk screws are available in different grades, such as 304 and 316, with 316 offering superior corrosion resistance.

Carbon Steel

Carbon steel is the most commonly used type of steel globally. It is known for its strength and versatility. Carbon steel Allen head countersunk screws are widely used and can be found in various applications, including wooden, metallic, and domestic settings.

High Tensile Steel

High tensile steel is a type of steel specifically known for its high tensile strength, making it ideal for applications that require strong and durable fasteners. Countersunk head socket screws made from high tensile steel are popular due to their strength, flat head shape, and compatibility with Allen keys.

Zinc

Zinc is a metallic element that can be used as a coating for Allen head countersunk screws. Zinc-plated screws offer enhanced corrosion resistance and a bright finish. They are often used in applications where corrosion protection is important while maintaining an aesthetically pleasing appearance.

Galvanised

Galvanised steel is a type of steel that has been coated with a layer of zinc to improve its corrosion resistance. Galvanised Allen head countersunk screws are commonly used in applications where protection against corrosion is crucial, ensuring the screws have a long service life.

In addition to these materials, Allen head countersunk screws can also be found in plain black uncoated finishes, offering a more subtle and understated appearance. The specific material chosen depends on the intended application and the desired properties, such as corrosion resistance, strength, and aesthetics.

Allen head countersunk screw applications

Allen head countersunk screws are used in a variety of applications, thanks to their ability to sit flush against a surface when screwed in. This feature makes them ideal for use in projects where a smooth, uninterrupted surface is desired.

One common application for Allen head countersunk screws is in woodworking. The screws can be used to join two pieces of wood together, with the countersunk head allowing the screw to sit flush with the surface of the wood. This is particularly useful for projects such as furniture making, where a smooth finish is desired.

Similarly, Allen head countersunk screws are also used in metalworking applications. The screws can be used to join two metal components together, with the countersunk head providing a flush finish. This is often used in projects such as machinery or vehicle manufacturing, where a smooth, uninterrupted surface is important for both aesthetic and functional reasons.

In addition, Allen head countersunk screws are also commonly used in marine applications. The screws are often made from corrosion-resistant materials, such as stainless steel or carbon steel, making them suitable for use in saltwater environments. The screws can be used to secure marine hardware, such as deck fittings or hull components, with the flush finish of the countersunk head helping to reduce drag and improve the efficiency of the vessel.

Another application for Allen head countersunk screws is in domestic settings. The screws can be used for a variety of tasks around the home, such as securing fixtures, assembling furniture, or making repairs. The ability of the screws to sit flush with the surface makes them ideal for use in areas where a smooth, unobtrusive finish is desired, such as in cabinetry or flooring.

Allen head countersunk screw manufacturers

Suraj Metal Corporation is a leading manufacturer of stainless steel and carbon steel Allen head countersunk screws, supplying different types of SS 304 Allen Head Countersunk Screw in various sizes and grades. The 304 material is an austenitic stainless steel that is strong and corrosion-resistant. There are also SS 316 Allen Key Countersunk Screw types, which are made of a more corrosion-resistant material. The screws can also be self-tapping.

Other manufacturers include Unbrako, Hobson, Brighton Best, Bremick, James Glen, and Inox World, which are stocked by NHTB.

Allen head countersunk screws are made from high tensile steel and are popular because of their excellent tensile strength, hex Allen key drive, and flat head shape. They are available in a range of materials, including Stainless Steel A2-70 G304, Marine Grade Stainless Steel A4-70 G316, Zinc Plated, and Plain Black.

Frequently asked questions