The Types and Features of Nord-Lock Washers
In the world of fasteners, there are many types of washers, but Nord-Lock washers are heavy-duty heroes. They are generally used in extreme conditions, such as in industrial applications with high dynamic loads and vibrations that can cause a normal friction-based bolt to become loose easily.
What are Nord-Lock Washers?
Designed in 1982 by Swedish company Böllhoff, Nord-Lock washers are unlike traditional types of washers with smooth sides, whose primary purpose is to distribute tightening loads equally. Nord-Lock washers (commonly used in a pair) have cams on one side and radial teeth on the other to keep bolts from loosening using tension instead of just friction from the bolt. This wedge-locking technology allows bolts to be used in situations where there are extreme vibrations or dynamic loads. Nord-Lock washers are widely used in construction, mining, and marine applications.
Imagine if a bolt came loose in these situations:
- A construction crane
- A roller-coaster in an amusement park
- A wheel on a heavy-duty dump truck
- The landing gear on a passenger airliner
- The rudder on an oil tanker
A bolt failure in any of these situations would be catastrophic and would more than likely result in the loss of human life. Although simple in design, bolts must stand up to all types of weather and extreme wear and tear.
Just like screws, bolts are integral to our everyday life and they need to withstand the stresses of our fast-paced society. Pairing them with Nord-Lock washers allows bolts to be used reliably and securely.
Types of Nord-Lock Washers
Nejireo carries a range of Nord-Lock washers with Böllhoff’s proprietary wedge-locking solution for different industry applications.
Standard Nord-Lock Washers
The standard Nord-Lock washers are meant to be used with standard bolts that are available in a wide range of sizes to fit almost any application. These washers are made from high-quality steel and are made with specific cam patterns on the inner and outer diameters of the washer.
When tightening pressure is applied, the cams on the inner diameter will wedge against the outer diameter of the second washer. This creates a high-tension force that locks the bolt in place and resists any movement and torque from the fastened piece. The Nord-Lock washers are able to maintain its tension even under extreme temperatures during thermal cycling. The high corrosion resistance demonstrated in the ISO 9227 test, which stipulates a minimum of 1,000 hours in salt spray, makes it suitable and durable for marine applications.
These standard Nord-Lock washers are suitable for various applications and are the most popular Nord-Lock washers in our inventory.
X-series Nord-Lock Washers
The X-series Nord-Lock washers are unique and offer greater tightening security compared to the standard Nord-Lock washers. They feature a second cam on the outer diameter of the second washer plate. The addition of this cam creates greater tension which makes the X-series Nord-Lock suitable for the most demanding applications, such as on ships or heavy-duty construction equipment.
Features of Nord-Lock Washers
Nord-Lock washers are designed for extreme use, where failure is not an option. That is why they are tested extensively using internationally recognized standards.
Junkers Test
This is the most severe vibration test for bolted joints. It’s commonly used as a way to compare how different locking methods behave under transverse vibrations between two construction parts while continuously measuring the clamp load.
During the test, Nord-Lock washers surpassed all their competitors because they all depend on friction instead of geometry to secure the bolted joint. The Nord-Lock proves that geometry is the more reliable method to control preload over time.
Wedge-Locking Function
Through the clever cam and radial teeth design, the wedge-locking function is immediately activated once both washers are pressed together. This prevents any independent movement of the individual washers, which is only possible due to the selection of materials with high hardness profiles.
When the proper tightening force is applied, the correct cam geometry prevents the bolt from vibrating loose by increasing the clamping load when rotation happens. This is known as the wedge-locking effect. This makes Nord-Lock washers dependable even in the most demanding situations and ensures a high standard of safety for our customers.
Nejireo.com carries a range of Nord-Lock washers to fulfill every industry application. We have no MOQ and are able to provide a range of fasteners from M1 - M100. Contact us today for a quotation.
