Washers

Washers are thin rings of material with a hole in the centre. They are an essential part of any fastener assembly and are used in conjunction with screws, nuts, and bolts. These small yet crucial components help distribute the force the fastener applies more uniformly, preventing damage to the surface they're attached to. This is particularly vital when fastening into softer materials like wood or aluminium, which are susceptible to stress and deformation. By evenly spreading the load, washers enhance the assembly’s overall durability and stability while protecting against loosening and corrosion over time.

Types of Washer

Washers come in various types, each designed to meet specific fastening and load-bearing needs.

• Plain/Flat washers: The most common type, characterised by a round shape with two flat sides. This type of mechanical washer is used for evenly distributing the load of screws and bolts, as well as reducing friction and heat buildup during tightening. They are widely used in both industrial and household settings, as well as provide electrical insulation where needed.
• Lock washers: These are designed with tiny ridges, called radial serrations, that dig into both the bolt head and the surface it contacts, creating a secure grip. This feature prevents bolts from loosening due to vibration, making lock washers ideal for applications like automotive, aerospace, and household appliances, such as washing machines, where stability is essential.
• Bonded washers: Consists of a metal washer with a rubber ring bonded to its inner edge. This design creates a strong, leak-proof seal, especially useful in automotive, hydraulic, and pneumatic systems.
• Cup washers: Has a rounded, cup-like shape that curves upward around the bolt or screw head, offering extra support and preventing pull-through. Their concave design is ideal for securing materials under light loads.
• Mudguard washers: Designed with a wider outer diameter than the inner hole. This extra width makes them an ideal heavy-duty washer for bolts, especially in applications like automotive repairs, construction, and securing sheet metal, as it helps spread the load to prevent pull-through or surface damage.
• Shoulder washers: Features a flat base with a raised sleeve on one side, allowing the shoulder washer to insulate fasteners, wires, or shafts from both moisture and electricity. Their design also provides a smooth bearing surface, which is ideal for rotary components.
• Spring washers: A coiled or split design that allows them to flex slightly, making them suitable washers for bolts that may experience movement due to vibration or changes in temperature.
• Tap washers: Are essential in taps to prevent leaks by creating a watertight seal. They are commonly used in kitchen and bathroom fixtures, ensuring controlled water flow and reducing waste.

How to Choose a Washer

It is important that your washer is compatible with your fasteners and your chosen application. Consider the following information when making your choice:

• Size - Fasteners such as screws and bolts are usually measured in metric dimensions, such as M10 (10mm) or M8 (8mm). Ensure your washer matches these sizes for a secure connection and optimal performance in your application.
• Material - Washers are primarily made from stainless steel or brass. Stainless steel washers are popular due to their durability and corrosion resistance. Other materials, such as ceramic, are also available. Additionally, washers come in various finishes, including chrome and nickel plating.
• Shape - The majority of washers are round to match the round head of a screw or bolt. You can also buy square washers for use with bolts with a square head.
• Thickness - Washers are available in a variety of thicknesses, from ultra-thin options around 0.25mm for precise, light-duty needs to thicker types up to 8mm or more, suited for heavy-duty and structural applications.
• Environment compatibility - One often overlooked factor is choosing a washer material suitable for its environment. For instance, using rubber washers in high-temperature or chemical settings can lead to degradation, compromising their effectiveness and lifespan.

Customer Question: Do Washers Go On the Bolt or Nut Side?

Depending on the specific need, washers can be placed on either the bolt or nut side.

Place washers on the nut side when using lock washers to prevent the nut from loosening due to vibration. For bolts being threaded directly into parts, such as a threaded hole or assembly, the washer should be on the bolt side. If you aim to protect the material’s surface, especially when it's delicate or thin, position the washer under the part of the fastener—either the bolt head or nut—that will be tightened against the material. This helps distribute the force more evenly and prevents damage.

Industry Applications

Washers are critical in various industries across Australia, ensuring operational efficiency.

• Machinery: Washers are used to stabilise heavy machine parts, reducing wear from constant movement and vibration.
• Automotive: In vehicles, washers are used to secure components subjected to regular movement and vibration, such as brakes and suspension systems, reducing the risk of loosening.
• Pharmaceuticals: To prevent leaks and ensure proper sealing, washers are essential in securing fittings and valves in pharmaceutical equipment, safeguarding the integrity of drug manufacturing processes.
• Energy: In high-stress environments like turbines, washers maintain secure fittings under high temperatures and pressure, ensuring the reliability of energy infrastructure.
• Manufacturing: Washers in manufacturing ensure components fit tightly, preventing loosening under mechanical stress. They are critical in assembly processes where they help maintain alignments, such as in attaching panels or securing gears.
• Aerospace: Given the extreme operating conditions in aerospace, washers are used to secure engine components and airframe assemblies, providing necessary resistance against the vibrations and temperature fluctuations encountered during flight.
• Electronics: Plastic or rubber washers are utilised to insulate electrical or hardware components within devices. They are essential for preventing electrical shorts between metallic parts and safeguarding sensitive electronics from environmental factors like moisture and dust.

Your Trusted Washers Supplier & Manufacturer

At RS, we are your trusted supplier, distributor, and manufacturer of washers in Australia. Alongside RS PRO’s selection, you can also choose from other leading brands such as Heico, Legris, ABB, and Siemens. We are committed to quality and customer satisfaction, making RS your go-to source for all your washer needs.

Browse washers online from our selection to find the ideal type for your specific needs. While at it, you can also check out options like hex nuts, p clips, cable clips and screwdrivers to complete your toolkit.

Visit our delivery service page to learn more about our quick, hassle-free shipping options.