As you tighten a bolt, these metric washers flatten to add tension to the threaded joint and prevent loosening from small amounts of vibration. All of these washers meet a DIN or ASME standard for split lock washer dimensions.

Standard split lock washers have a left-hand helix, which means you can only use them with bolts that have right-hand threads to prevent clockwise rotation from vibration. When tightened, their uneven split ends bite into unhardened nuts and bolts for a tighter hold than curved or wave washers, but only for applications with clockwise rotation. The washers, nuts, and bolts will be deformed when untightened, so none of them can be reused. Do not use these washers on hardened surfaces.

Curved and wave split lock washers can be used with bolts that have right- or left-hand threads to prevent clockwise or counterclockwise rotation from vibration. Although they don’t grip as tight as standard split lock washers for applications with clockwise rotation, they are best for those with counterclockwise rotation. These washers retain their shape when untightened and will not damage nuts and bolts, so all can be reused. Wave washers grip tighter than curved washers because they make contact with your surface at more points. Their wave design also means they compensate for uneven surfaces and tolerance variations.

Stainless steel washers are more corrosion resistant than steel, and nearly as strong. 18-8 stainless steel washers are good for humid, damp, and washdown environments, but will corrode when exposed to salt water and other chlorine solutions.

Use zinc-plated and yellow zinc-plated steel washers in mostly dry environments. The zinc plating offers temporary rust protection, but once it wears away the steel will rust. All of these washers are stronger and more wear resistant than stainless steel.

Steel washers are stronger and more wear resistant than zinc-plated steel and stainless steel. Use them in dry environments because they will rust in wet and corrosive environments. Blue-dyed steel washers are easy to spot. Black steel washers have a black residue that forms from being heat treated; the color will wear away over time.

For technical drawings and 3-D models, click on a part number.

The arched shape of these washers presses up against a bolt and down against a nut to prevent loosening from wear, vibration, or temperature changes. Similar to a spring, they flatten out as pressure is applied, helping to absorb shocks. They grip bolts more tightly than split and tooth lock washers. Unlike split lock washers, which can only be tightened in one direction, these washers have a continuous body that can rotate in either direction.

Conical and curved washers are functionally the same, and are often referenced using their DIN specifications. These DIN specifications refer to slight differences in OD and thickness. DIN 6796 is the standard for conical spring lock washers, which are also known as Belleville washers.

Steel washers are stronger and more wear resistant than zinc-plated steel and stainless steel. They are best for dry environments, since moisture will cause them to rust. Zinc-plated washers have an outer layer of zinc that protects the inner steel from rust and extends the life of the washer. Similar to zinc plating, washers with a black phosphate coating are protected from rust in wet environments. They have a black finish that blends in with dark surfaces.

Stainless steel washers are more corrosion resistant than steel, and almost as strong. 18-8 stainless steel washers will hold up in wet and humid environments, but will corrode if exposed to salt water or chemicals. 316 stainless steel washers are the most corrosion resistant, and will not corrode from water, salt, or chemicals.

For technical drawings and 3-D models, click on a part number.