The Ultimate Guide To Washer Head Type 17 Screws

The 8x1 washer head type 17 screw is a type of fastener with a specific set of features and applications. It is commonly used in construction, woodworking, and other industrial applications. This screw features a round washer head design, which provides a decorative appearance and prevents the screw from sinking into the material. The type 17 point, also known as a cutter point, allows the screw to be driven into dense woods without pre-drilling, reducing the risk of wood splitting. The screw's zinc finish adds corrosion resistance and enhances the overall appearance of the fastener.

Round washer head design

The round washer head design is possibly the most versatile head design available. A washer is formed as part of the head itself, providing a larger bearing area that is especially useful when fastening soft materials. The flat bearing surface under the head prevents the screw from being countersunk.

Round washer-head screws have a raised pan head with an integral washer formed during the heading process. This large bearing surface prevents the screw from being over-driven and makes them perfect for fastening almost any type of mounting bracket.

They are commonly used when hanging kitchen and bathroom cabinets and are often used for pocket-hole joinery in exterior projects. They are also great for attaching countertops and are known as drawer front screws because of their common use in attaching drawer fronts to box-style drawers. The oversized round washer-style head makes this screw perfect for accommodating minor wood movement, or installation adjustment.

Type 17 cutter point

The 8x1 washer head type 17 screw features a Type 17 cutter point, which is a specific design that serves a unique purpose. While the type 17 designation refers specifically to the point shape, it is integral to the function and applications of the screw as a whole.

The Type 17 cutter point is characterised by a sharp, pointed design with a cut-out flute, similar to a drill bit. This design feature enables the screw to capture and remove waste material, allowing for a self-drilling function. The sharp point and flute cut-out work together to efficiently clear chips and debris when drilling, reducing torsion on the screw head and driver.

This type of point is commonly used in self-drilling wood screws, especially for hard timbers like hardwoods. The Type 17 point's ability to clear chips and debris prevents binding, making it ideal for drilling into lumber with minimal effort. In addition to wood, the Type 17 screw can also fasten thin steel and soft metals like aluminium.

The Type 17 cutter point's sharp point makes it suitable for use in thin steel sheeting without the need for pre-drilling. This makes it a popular choice for applications such as fixing roofing and cladding sheets. Furthermore, the Type 17 point helps prevent wood fibres from separating, reducing the likelihood of splitting. As a result, these screws are well-suited for close-to-edge work and provide fast insertion and self-centring starts, making them compatible with power drivers.

Square drive

The square drive is a key feature of the 8x1 washer head type 17 screw. This type of screw has a unique drive style that sets it apart from other fasteners. The square drive is designed to be durable and efficient, offering several advantages over other drive types.

One of the standout features of the square drive is its ability to resist cam-out. Cam-out occurs when the driver slips out of the screw head due to the force of torque. With a square drive, the risk of cam-out is significantly reduced due to the secure and stable engagement between the driver and the screw head. This makes the 8x1 washer head type 17 screw an excellent choice for applications where a firm and consistent connection is crucial.

The square drive also offers enhanced torque transfer compared to other drive types. The square shape of the drive allows for a more even distribution of force, resulting in increased torque transmission. This feature is particularly advantageous when working with harder materials or when a higher torque is required for secure fastening.

In addition, the square drive provides excellent resistance to stripping. Stripping occurs when the screw head becomes damaged or deformed due to excessive torque or misuse of tools. The square drive's robust design helps to prevent stripping, ensuring that the screw head remains intact and functional even under significant pressure or when subjected to high levels of torque.

Another benefit of the square drive is its compatibility with a variety of tools and fasteners. Square drive bits and drivers are widely available, making it convenient for users to find the right tools for the job. Additionally, the square drive is commonly used in a range of applications, from construction and woodworking to automotive and mechanical engineering. This versatility makes the 8x1 washer head type 17 screw a popular choice for professionals and DIY enthusiasts alike.

Corrosion resistance

The 8x1 washer head type 17 screw is a type of screw with a specific head design and size. The washer head provides a larger bearing surface, which helps to distribute the load and prevent the screw from pulling through the material. The "8x1" designation refers to the screw size, with "8" indicating the diameter and "1" the length. Type 17 refers to the type of screw point, which determines how the screw penetrates and pierces the material it is being driven into.

When it comes to corrosion resistance, there are several factors to consider for 8x1 washer head type 17 screws:

Material Choice

The choice of material for the screw is critical to its corrosion resistance. Stainless steel is a common material for screws and offers good corrosion resistance due to its chromium content. The minimum chromium level for stainless steel is 10.5%. The addition of other elements, such as molybdenum, titanium, nickel, or copper, can further enhance corrosion resistance.

For instance, 304 and 305-grade stainless steel screws are suitable for general use, with 305-grade offering slightly better corrosion resistance. If maximum corrosion resistance is required, 316-grade stainless steel is recommended, although it comes at a higher cost.

Coatings and Plating

Applying coatings or plating to the screws can significantly enhance their corrosion resistance. For example, zinc plating or coatings provide a sacrificial layer that corrodes before the underlying screw material, thus protecting it. Hot-dip galvanizing and mechanical galvanizing are processes that create a thick zinc coating, providing excellent corrosion resistance for screws.

Additionally, some screws are epoxy-coated or use specially formulated coatings to resist rust and corrosion. These coatings act as a barrier between the screw and the environment, preventing moisture and corrosive substances from reaching the screw material.

Environmental Factors

The environment in which the 8x1 washer head type 17 screws will be used is a crucial consideration for corrosion resistance. If the screws will be exposed to saltwater or marine environments, certain materials and coatings are more suitable. For example, A4 stainless steel, also known as marine-grade stainless steel, is often used in constructions around water due to its exceptional corrosion resistance in saltwater.

Similarly, specialty metal fasteners, such as nickel alloys, titanium, zirconium, and tantalum, are designed to withstand harsh chemical environments, including exposure to strong acids and saltwater applications.

Installation and Usage

The way the screws are installed and used also affects their corrosion resistance. It is essential to ensure that screws are installed correctly and with constant pressure. Variable load on a fastener can accelerate corrosion. Additionally, the flow of electricity and corrosion rate are higher when moving from a smaller object to a larger one. Therefore, it is crucial to consider the electric potential of the screw and the material it will be fastened to. Using screws with similar electrochemical properties to the material being fastened can help reduce corrosion.

In summary, achieving corrosion resistance for 8x1 washer head type 17 screws involves selecting the right screw material, such as stainless steel with appropriate alloying elements, and applying effective coatings or plating, such as zinc or specialized formulas. Additionally, considering the environmental conditions and following best practices during installation can further enhance the corrosion resistance of these screws.

Stainless steel composition

The composition of stainless steel varies depending on the specific type and grade of stainless steel. In the context of the 8x1 washer head type 17 screw, the stainless steel composition typically refers to the grade of stainless steel used, which in this case is 305 stainless steel.

Grade 305 stainless steel, also known as 18-8 stainless steel, is a common grade of stainless steel that offers excellent corrosion resistance and good strength properties. It is often used in outdoor or damp applications, making it suitable for screws that need to withstand exposure to the elements.

The composition of 305 stainless steel typically includes:

• Chromium: Chromium is the element that gives stainless steel its corrosion resistance properties. It forms a protective oxide layer on the surface of the steel, known as the passive layer, which prevents oxidation and rust formation.
• Nickel: Nickel is added to stainless steel to enhance its corrosion resistance, especially in acidic environments. It also improves the ductility and toughness of the steel.
• Iron: Iron is the base metal in stainless steel and makes up the majority of its composition. It provides strength and magnetic properties to the alloy.
• Carbon: Carbon is present in small amounts in 305 stainless steel and helps to harden the alloy. However, it can also make the steel more susceptible to corrosion, so the carbon content is carefully controlled.
• Other Elements: In addition to the main elements mentioned above, small amounts of other elements such as manganese, silicon, and molybdenum may be present in the stainless steel composition. These elements are added to enhance specific properties, such as strength, formability, or corrosion resistance.

The composition of 305 stainless steel is designed to provide a balance of corrosion resistance, strength, and workability, making it a versatile and widely used grade of stainless steel for applications such as screws, fasteners, and other hardware components.

Frequently asked questions