Your result
Locking ability |
3 out of 5 |
Reusability |
1 out of 5 |
Worker safety |
4 out of 5 |
Initial cost |
Medium |
Lifetime cost |
Medium |
Serrated lock washer
What is a serrated lock washer, and how effective are they against bolt loosening?
Are serrated washers effective
against bolt loosening?
Serrated lock washers increase the friction between the bolt head/nut and the mating surface. They do this by gripping into the mating surfaces. Serrated lock 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. If the bolted joint experiences a loss of tension, the washer is no longer effective and must be replaced.
Single part serrated washers can damage painted/coated surfaces because they have a tendency to rotate with the fastener. This risks damaging the surface, cracking the paint/coating and causing corrosion.
Read the full version in the eBook "Why do bolts loosen?"
(A comparison between common bolt securing options)
Scroll down to access the ebook.
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
SPEND A LOT OF TIME CHECKING YOUR BOLTS AND NUTS ARE STILL TIGHT?
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.
