Split washers, also known as split lock washers or spring lock washers, feature a single cut that extending from the outside diameter to the center hole. The two ends are misaligned and exert the washer to create a special helical shape - like a donut. And it is this misalignment allows for a positive locking section - creating more friction for better resistance to rotation & loosening.

Split washers are extensively used where loosening from vibration and corrosion are primary concerns. Meanwhile, they match well with socket head cap screws and ideal for areas with installation space limitations.