Your result
Locking ability |
Not applicable |
Reusability |
4 out of 5 |
Worker safety |
4 out of 5 |
Initial cost |
low |
Lifetime cost |
high |
Plain washers
What is a plain washer, and how effective are they against bolt loosening?
Your result
Are plain washers effective
against bolt loosening?
Plain washers, also known as flat washers, are the most common type of washer. Plain washers do not have a locking function, rather they are used to protect the mating surface from damage. They do this by increasing the surface area in order to help distribute the load, in particular on soft materials or over large or slotted holes. Plain washers are installed between the bolt head/nut and the mating surface. The bolted joint is then tightened in the same way as an unsecured bolt.
Scroll down to access the eBook "Why do bolts loosen?"
(A comparison between common bolt securing options)
Which bolt locking product should I use?
- Pros & Cons of different bolt locking methods
- A Guidance for Selection, to help you decide which product to use in your applications
Get the free eBook
DO YOU EXPERIENCE BOLT LOOSENING? PLAIN WASHERS HAVE NO LOCKING FUNCTION!
The biggest challenge for a bolted joint, causing it to lose preload and fail, is spontaneous loosening often caused by vibrations. This Junker test shows all 5 nuts rotated loose! A steep decline in the graph indicates a failure. Read more about the Junker Test.
