Washer conundrum solved: should the lock washer go before the flat one?

When it comes to securing bolts and nuts, washers play a crucial role in ensuring a tight and reliable connection. But with different types of washers available, a common question arises: does lock washer go before flat washer? In this comprehensive blog post, we’ll delve into the purpose of both washers, their proper order, and the factors that determine their placement.

Purpose of a Flat Washer

A flat washer is a thin, circular disk that serves several purposes:

• Distribute Load: It increases the contact surface area between the bolt head or nut and the mating surface, distributing the load evenly to prevent damage or deformation.
• Prevent Bolt/Nut Embedding: It acts as a barrier between the bolt/nut and the surface, preventing them from sinking into soft materials.
• Isolate Electrical Connections: It provides electrical isolation when used with bolts or nuts in electrical applications.

Purpose of a Lock Washer

A lock washer is a type of washer designed to prevent bolted connections from loosening due to vibration or movement. It works by creating a friction-based lock between the bolt/nut and the mating surface. There are two main types of lock washers:

• Split Lock Washer: This washer has a split ring that creates tension when compressed, locking the bolt/nut in place.
• Star Lock Washer: This washer has a star-shaped design with sharp points that dig into the mating surface, preventing the bolt/nut from rotating.

Does Lock Washer Go Before Flat Washer?

The general rule of thumb is to place the lock washer before the flat washer. This order ensures that the lock washer’s friction-locking mechanism is closest to the bolt/nut, while the flat washer provides load distribution and electrical isolation.

Exceptions to the Rule

In certain situations, the order may need to be reversed:

• When the surface is very soft: If the mating surface is soft, the flat washer should be placed first to prevent the lock washer from embedding and compromising its locking ability.
• When electrical isolation is critical: In electrical applications, the flat washer should be placed first to provide electrical isolation, followed by the lock washer to prevent loosening.

Factors to Consider When Choosing Washer Order

The following factors should be considered when determining the order of washers:

• Load: The amount of load being applied to the connection.
• Surface Material: The hardness or softness of the mating surface.
• Electrical Requirements: The need for electrical isolation.
• Vibration or Movement: The likelihood of the connection being subjected to vibration or movement.

Installation Tips

• Use the Correct Size: Ensure that the washers are the correct size for the bolt/nut and mating surface.
• Tighten Properly: Tighten the bolt/nut to the manufacturer’s recommended torque to ensure a secure connection.
• Inspect Regularly: Periodically inspect the washers and connection to ensure they are still functioning properly.

In a nutshell: The Importance of Proper Washer Order

Understanding the proper order of washers is essential for ensuring the reliability and longevity of bolted connections. By following the guidelines outlined in this blog post, you can confidently determine the correct placement of lock washers and flat washers, ensuring optimal performance and preventing potential problems.

Basics You Wanted To Know

1. Why is it important to use both lock washers and flat washers?
Lock washers provide locking, while flat washers distribute load and prevent embedding. Using both ensures a secure and reliable connection.

2. What happens if I put the lock washer after the flat washer?
In most cases, the lock washer will still be able to function, but its locking effectiveness may be reduced.

3. Can I use multiple lock washers?
Using multiple lock washers is not recommended. It can create excessive friction and damage the bolt/nut or mating surface.

4. What is the difference between a split lock washer and a star lock washer?
Split lock washers create tension, while star lock washers dig into the surface. Star lock washers provide a more secure lock.

5. How do I know if my washers are worn out?
Worn-out washers may have cracks, deformation, or reduced thickness. Replace them as necessary.