Every mechanical solution in the modern day is backed by hardware components that channels steadiness, safety, and promptness into the machinery. One such crucial bit of hardware component is the industrial washer which helps even out the load put on by threaded fasteners, such as a bolt. Washers, which can typically be described as round disks with a centered hole, are also crucial for galvanic corrosion prevention.

Now, these disk-shaped plates, extensively used to prevent loosening of fasteners are often made available in diverse ranges of varying metals or non-metal built including varying physical attributes like thickness, outside/inside diameter and so on. This ensures washers of divergent kinds can easily find their perfect machine fit, even if the machine model or make varies in number. This is why it is absolutely integral for users to determine the perfect type and the optimal capacity of the washer before its application. 

Washer types, even though, range multiple in number, there are three primary categorizations of washer types, namely- Plain, Spring, & Lock type. Washers extensively used both in industrial and commercial setting stems down from these three primary washer groups. 

Let us break down each washer group with an extensive overview of the different sub-types and their application genres in this thread. 

Plain Washer 

Plain Washers, also commonly known as Flat Washers, are considered to be one of the most common washer types out there with a large bearing surface area allowing the washer to uniformly distribute the load or force of the fastener. This also promotes the prevention of unnecessary damage caused by excess friction or heat during the installation. The most common sub-categories of Plain washers can be- 

  • Fender Washer – Extensively used in automobiles, sheet metal, plumbing, electrical equipment, drywall, signboards, and more, these washers come with a larger outside diameter and a constricted hole in the center, implying small inside diameter and possess a relatively large area in comparison to flat washers. 
  • C Washer- These washers are designed much like the alphabet c with the design allowing feasible sliding in and sliding out of the washer. This washer is mostly used in situations where the assembly requires independent, easy insert support or brace for the fasteners, the repositioning or removal of which will not result in disassembly of the assembly. 
  • Shoulder Washer- Made available in phenolic, nylon, fiberglass, PTFE, PCTFE, and metal, shoulder washers come with an integrated surface sleeve and is used extensively for insulating screws, wires, or any other part of the machine or component that might react to friction or heat. 
  • Countersunk Washer- These washers almost work as flat washers with a 90 to 120 degree countersunk on top providing a flush surface for a similar oval or flat countersunk fastener. These hardware components are available in varying designs from angle countersunk, un-flanged countersunk and rolled countersunk to angle countersunk. 

Spring Washer 

Spring washers, also commonly referred to as disc springs are considered to be crucial for fastener assemblies that require axial flexibility. Spring washers are particularly chiseled to match the pressure or tension of the fastener as they continue to fill in for irregular materials or unstable assemblies undergoing deformation. These washers are also good for vibration or shock absorption and the main sub-types of these washers that are extensively used are, namely, 

  • Belleville Washers- Also commonly referred to as Belleville disks or conical springs, these washers are built to endure the dynamic tension in the assembly caused due thermal contraction or expansion. The cone-shaped design of these washers allows them to support larger loads with negligible deflection. 
  • Finger Spring Washers- Spring washers, manufactured from carbon steel is designed with 3-6 protruding fingers or flanges and are extensively used to absorb noise, vibration, and excess wear and tear. These washers are also used to prevent or mitigate wearing down or skidding wear caused by rotating components. 
  • Wave Spring Washers- Working as a cushion spring, these washers have a moderate load capacity and a modest deflection range that prevents the fastener from loosening. The Curvilinear disk design sported by the wave spring washers is also crucial for the absorption of noise and vibration.  
  • Curved Spring Washers- Commonly referred to as crescent spring washers, these come with a small-load support capability and a wide deflection range that allows suitable flexibility and effortless load-cycle applications. The Curved Spring washer is also known to provide a uniform sprint rate over the deflection range.
  • Dome Spring Washers- Dome Spring Washers usually come with high load capacity and a small deflection range, even though the design of the dome washer is somewhat similar to crescent washers. These washers, however, have ground curves which can create a flatter load-bearing surface. 

Lock Washers 

Lock Washers or better known as, locking washers are almost similar to spring washers with their primary application being the prevention of fastener loosening. These washers help prevent loosening of fasteners owing to rotation or loss of friction. The main sub-types under this category that is commonly used in the industry are: 

  • Tooth Washers- Tooth washers, also commonly known as star washers, are designed with an angled tooth that bites into the fastener or the mounting surface and prevents loosening. These washers are primarily known for their teeth structure and are segregated into two broad classifications, namely, External tooth lock washer working best on larger head screws and Internal tooth lock washer working towards the absorption of shock and vibration effectively. 
  • Split Washers- Split washers are also known as Helical washers that prevent loosening of assembly components. It works around an increased preload and bites into the mounting surface to prevent loosening grips due to vibration or corrosion.