Fastener Type: Hex Serrated Flange Nut. Thread Diameter: 5/16"; Thread Size: 18 threads per inch; Flange Diameter(A): 17mm/0.67". Width Across Flat Size (B) : 12.5mm/0.49"; Nut Height (M) : 17mm/0.67". Constructed from carbon steel, zinc plated finish, good rust resistance, and durable to use.. Self-locking serrated flange digs into the material being fastened to help prevent loosening..
