These washers are manufactured and tested to strict U.S. military standards for material and construction. As you tighten, the uneven ends bite into the nut or screw so it won't loosen due to mild vibration. While they don't hold as tightly as other lock washers, they are a great fit for electrical panels, light fixtures, and other light duty assemblies. Split lock washers are not reusable, and they only work with fasteners that have right-hand threads.

Passivated 18-8 Stainless Steel—The choice for wet and outdoor environments, these washers won't rust when exposed to moisture. However, they can't hold up to the harsh chemicals that 316 stainless steel can.

Black-Oxide 18-8 Stainless Steel—Typically chosen for their appearance, these washers have a dark, matte coating to create a finished look. They won't rust in wet and outdoor environments, but can't hold up to harsh chemicals as well as 316 stainless steel.

Super-Corrosion-Resistant Passivated 316 Stainless Steel—Superior to 18-8 stainless steel, these washers won't degrade when exposed to harsh weather, salt water, and most chemicals.

Super-Corrosion-Resistant Black-Oxide 316 Stainless Steel—Combines a finished appearance with the rust resistance of 316 stainless steel. Even if the coating wears off, these washers will hold up in just about any environment, including salt water and most chemicals.