The primary difference between a spring washer and an ordinary washer lies in their designs and functions when used with nuts and bolts:
Ordinary Washer: An ordinary washer, also known as a flat washer, is a flat, circular metal or plastic disk with a central hole. It has a simple design and does not have any special features like teeth or splits. The main purpose of an ordinary washer is to distribute the load of the nut or bolt evenly over a larger surface area. This helps prevent damage to the material being fastened and ensures a more secure connection. Ordinary washers do not provide any significant locking or anti-loosening features.
Spring Washer: A spring washer, also known as a lock washer or helical spring washer, is a washer made from a circular piece of metal with a gap or split cut, forming a helix-like shape. When a fastener is tightened against the spring washer, it compresses and exerts spring pressure, creating tension that helps prevent the nut or bolt from loosening due to vibrations. The spring action of the washer provides a locking effect, increasing the friction between the fastener and the material being fastened.
Now, let's explore why they are used at all:
Ordinary Washer Uses:
- Load Distribution: As mentioned earlier, the primary purpose of ordinary washers is to distribute the load evenly over a larger surface area. This helps prevent the nut or bolt from sinking into softer materials and maintains a more uniform clamping force.
- Protecting Surfaces: Ordinary washers help protect the surfaces of the materials being fastened, reducing the risk of damage or deformation.
- Reducing Friction: They also serve to reduce the friction between the fastener and the material, making it easier to tighten the nut or bolt.
Spring Washer Uses:
- Anti-Loosening: Spring washers are used to prevent nuts and bolts from loosening due to vibrations or other external forces. The spring tension keeps the fastener in place, maintaining a more secure connection over time.
- Critical Applications: In situations where it is crucial to avoid fastener loosening, such as in heavy machinery, automotive applications, or industrial equipment, spring washers can provide an added layer of security.
Choosing the right type of washer for a specific application or material depends on various factors:
Ordinary Washers: These are commonly used in general fastening applications where vibration or loosening is not a significant concern. They are suitable for many household or light-duty projects and can be used with most materials.
Spring Washers: These are preferred in applications where vibration resistance is essential. They are commonly used in automotive, industrial, and heavy machinery applications. Spring washers are suitable for materials where increased friction is required to prevent loosening, but they might not be ideal for soft or brittle materials where the pressure from the washer could cause damage.
It's worth noting that in many critical or high-stress applications, more advanced fastening methods like using lock nuts or adhesives are preferred over spring washers due to their more reliable performance.