Types of Lockwashers

A washer is a thin plate with a central hole used to distribute the pressure load between two attached surfaces. They are often used with nuts, bolts, or other fasteners to prevent them from being driven into the material of the surfaces to which they are affixed. General wear and tear from vibration and friction often causes standard threaded fasteners to loosen over time, but the lock washer is designed to resist this. This blog will explain how lock washers work, their types, and how to use them.

Lock washers are configured to be tightened to a given torque beneath an ordinary fastener. They are not used instead of normal washers, but in conjunction with them. The lock washer exerts a spring tension that keeps the top fastener from vibrating loose. Most commonly, lock washers are attached to the nut side of the fastener. To withstand the harsh environments in which they are used, lock washers are made from hard metals such as stainless steel, galvanized steel, zinc-plated steel, and silicone bronze. Lock washers are key in automotive, aircraft, and marine transportation due to the constant vibration they are exposed to.

The two main types of lock washers are split washers (also known as spring action washers) and tooth washers. Split lock washers are helical-shaped split rings. When fastened, the ends of the ends of the asher exert a spring force on the fastener to create more friction and resistance to motion. The helical spring lock washer is the most common type of lock washer and is used very often during applications with smaller loads.

Lock washers for internal use feature teeth-like apparatus that ‘bite’ into the nut or screw head and the surface it contacts. These work well on small screws and are frequently found affixed to screws in electrical grounding. Lock washers for external use have teeth made to bite into the bearing surface, rather than the connected surface. An external tooth lock washer provides stronger holds than internal tooth washer because the teeth can attach to a larger radius, making them more suited to large screws. These tooth washers can leave scratches and other imperfections on the surfaces they are attached to.

There are five important steps to take when installing a lock washer. The first is very simple - just determine where you want to apply the item and which type of lock washer is best for this application. Second, measure the width of the bolt’s shank to know what size washer you need. Next, place the lock washer under the fastener, making sure it has a snug fit. Finally, turn the fastener with a ratchet or wrench until a firm connection is achieved. Once the washer is tightened in place, make sure the washer is intact and will hold correctly. For instance, if a split washer has been flattened during installation, it will not lock properly, and must be replaced. To remove a lock washer, there are multiple methods. You can use a wrench to remove the nut or pry it free with a flathead screwdriver, working the screwdriver head under the circumference of the washer.