To protect nuts and bolts from loosening, you may want to use lock washers. Washers, of course, are designed to distribute the load of a threaded fastener. You can place a washer around a threaded fastener, such as a bolt, and you can secure the end with a nut.
Lock washers, however, go one step further by preventing the fasteners with which they are used from loosening. Vibrations can typically cause fasteners to loosen. Lock washers prevent this from happening by locking the fasteners in place. How do you choose lock washers exactly?
The Style
You should consider the style when choosing lock washers. While they are all designed to protect fasteners from loosening, lock washers are available in different styles.
There are split lock washers that feature a split-like opening along the perimeter, and there are toothed lock washers that feature gripping teeth. Tooth lock washers can further be categorized as internal or external tooth depending on the location of these gripping teeth. Internal tooth lock washers have teeth on the inside, whereas external tooth lock washers have teeth on the outside.
The Material
Lock washers are also available in different materials. When shopping for them, you should choose a material that’s appropriate for the application in which they will be used.
Common materials in which lock washers are made include stainless steel, carbon steel and brass. Each material offers its own advantages. Stainless steel offers better protection against corrosion. Carbon steel, on the other hand, is stronger and more durable. Brass features many of the same benefits as zinc and copper, making it a versatile choice of material.
The Size
You can’t ignore the size when choosing lock washers. Like traditional washers, they are designed for use around threaded fasteners, such as bolts. Therefore, lock washers must match the size of the threaded fasteners with which they are used.
If a lock washer is too big, it may fit loosely around the threaded fastener. If it’s too small, it may not fit around the threaded fastener at all. You can avoid problems such as these by choosing lock washers in the right size.
In Conclusion
Lock washers are commonly used in the aerospace industry. Whether split or tooth style, all lock washers can resist vibrations. They will counter the vibration forces to which they are exposed, thus preventing the adjacent fasteners from loosening.