UNC Half Nuts (Lock Nut) ASME B18. 2.2 in Bright Zinc Plated (BZP) Steel
Nut conforming to ASME B18.2.2. Also known as a half nut, thin nut, or jam nut. Typically fitted with a spanner or ratchet with socket, often used in pairs in a nut locking arrangement. A popular nut type, and used for decades on all types of assembly throughout the world.