Airplanes require the use of special fasteners. During flight, airplanes will produce vibrations. Excessive or prolonged vibrations, of course, may result in fasteners loosening. Fortunately, there are anti-vibration fasteners available, such as lock washers.
Lock washers are used in conjunction with a bolt. Unlike regular washers, though, they are designed specifically to resist vibrations. Lock washers will prevent bolts from loosening when exposed to vibrations. Here are several common types of lock washers.
#1) Split
Split lock washers are characterized by a split design. They consist of a ring-shaped piece of metal with a small section cut out. Split lock washers aren’t completely flat, either. They are typically bent to achieve a helical shape. They are able to resist vibrations while subsequently securing bolts in place.
#2) Internal Tooth
Internal tooth lock washers feature teeth that point inward. You can use them like most other washers by placing them around a bolt. With their inward-pointing teeth, internal tooth lock washers will dig into surfaces. The photo above depicts a set of internal tooth lock washers.
#3) External Tooth
In addition to internal tooth lock washers, there are also external tooth lock washers. As you may have guessed, external tooth lock washers feature outward-pointing teeth. They are the same as internal tooth lock washers but with reversed teeth. Internal tooth lock washers have inward-pointing teeth, whereas external tooth lock washers have outward-pointing teeth. They are both able to resist vibrations; they simply feature different teeth styles.
#4) Wave
Wave washers feature a unique wave design. They aren’t completely circular, nor are they flat. Wave washers are designed with an axial wave. With this wave design, they act as a compression spring. Wave washers will compress the head of the bolt and the adjacent surface by pushing against them. This compressive force will protect the bolt from loosening when exposed to vibrations.
#5) Belleville
Belleville washers are a common type of lock washer. Also known as disc spring washers, belleville washers are characterized by a cupped design. They feature a canonical shape that’s higher along the inner hole and lower along the outer perimeter. Belleville washers have been around for over a century, making them one of the oldest types of lock washers.
Vibrations can loosen fasteners. Over time, vibrations can cause fasteners to separate and come out of the parts with which they are used. Lock washers, though, offer a solution. They will hold the fasteners in place by resisting vibrations.
