The LOCK WASHER INTERNAL STAINLESS #10 INTERNAL TOOTHED offers a reliable solution for secure fastening in applications where appearance matters. Made from high-quality stainless steel, this hardened washer features inward-extending prongs that provide a firm grip while remaining concealed under the screw head. With an inside diameter ranging from .221 to .231 inches and an outside diameter from .394 to .410 inches, it is ideal for various industrial and automotive uses where durability and strength are required.