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

Standard split lock washers match with fasteners that have right-hand threads to prevent clockwise rotation. They have uneven split ends that bite into fasteners for a tight grip but won’t work with hardened surfaces. They hold better than curved or wave washers. These washers are not reusable after tightening.

Curved and wave split lock washers can be used with fasteners that have right- or left-hand threads to prevent clockwise and counterclockwise rotation. These washers are reusable—they retain their shape when untightened and will not damage fasteners. Wave washers touch fasteners at more points, so they grip tighter than curved washers. Their shape also compensates for uneven surfaces and tolerance variations.

Stainless steel washers resist corrosion better than steel and are nearly as strong. 18-8 stainless steel washers withstand humid, damp, and washdown environments but will corrode when exposed to salt water and other chlorine solutions. 316 stainless steel washers resist corrosion from wet environments as well as salt water, chlorine solutions, and chemicals. Stronger and more durable than stainless steel, zinc-plated and yellow zinc-plated steel washers withstand wet environments. However, they will corrode in salt water and chlorine solutions. The zinc plating temporarily protects against rust, but once it wears off, the steel will rust.

Steel washers are stronger and resist wear better than zinc-plated steel and stainless steel washers. Use them in dry 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.