Self-locking hexagon nut (locknut) with Unified National Fine (UNF) thread, an American screw thread with fine pitch. Fitted with a nylon ring to prevent loosening due to vibration etc. Thread diameter-3/4 Inch Thread type-UNF Wrench/Spanner size-1-1/8 Inch Height-22.6 mm Material-Steel Surface treatment-Zinc-plated Quality-8.8 DIN standard-985