Self-locking nut made entirely of metal without nylon insert. Partial thread deformation creates persistent friction torque to resist loosening caused by vibration and impact. Can be used under high temperature conditions where nylon lock nuts cannot work. Available in strength Class 8, 10, 12. Carbon steel and alloy steel materials. Surface treatments: black oxide, zinc plating. Widely used in automobiles, engineering machinery, transportation equipment and high-temperature equipment.