Diameter: 6mm
Diameter 2: 11mm
Thickness: 6mm
Material: Steel
Finish: Black Phosphate
Driver Type: #10 Wrench
Thread Size: 1.0mm (Coarse)
Hardness: Class 8
Style: Nylon Insert
Type: Lock Nut
Specifications: DIN 985

Box of 1093.

A lock nut is a nut that resists loosening under vibrations and torque.