Spring washers are specifically designed components of a fastener assembly used to prevent loosening due to vibration and thermal expansion.
Based on standard practice and the provided reference, spring washers should be used on the nut side of the fastener.
Proper Placement of Spring Washers
The precise location of a spring washer in a bolt, washer, and nut assembly is crucial for its effectiveness.
- Primary Location: The spring washer is placed on the nut side of the bolt or screw.
- Position Relative to Nut: It should be positioned next to the nut. This means the spring washer is between the nut and the material surface or any other washer that might be present on the nut side.
Assembly Order Example
If you are using multiple components in your fastener assembly, the order on the nut side typically follows a specific sequence.
Let's consider a scenario where you have a bolt passing through two surfaces, a nut, a spring washer, and an additional plain washer for load spreading on the nut side. The correct order from the surface outward towards the nut would be:
- Surface/Material 1 (where the bolt head rests)
- Surface/Material 2 (being joined)
- Load Spreading Washer (if used on the nut side)
- Spring Washer
- Nut
Note: The reference states: "If an additional washer is required to spread the load... it should be used between the spring washer and the mounting surface, i.e. the spring washer should be positioned next to the nut."
Visual Representation of Placement
| Component Order (Nut Side) | Purpose |
|---|---|
| Material Surface | Base material or component being joined |
| Plain/Load Spreading Washer | Distributes load over a larger area |
| Spring Washer | Provides tension to resist loosening |
| Nut | Secures the assembly |
Why This Placement Matters
Placing the spring washer directly under the nut allows it to exert pressure against the nut as the nut is tightened. This pressure helps maintain tension in the bolt assembly, which is essential for preventing the nut from vibrating loose. The spring action accommodates minor shifts or expansion, keeping the joint snug.
Common Applications
Spring washers are widely used in various applications where vibration is a concern, such as:
- Automotive parts
- Machinery
- Appliances
- Structural steelwork (less common for large structures compared to other methods, but used in components)
Understanding the correct placement ensures that the spring washer performs its intended function effectively, maintaining the integrity of the fastened joint.
