Qualfast: M4 Lock Nut N/M Insert BZP (5) Lock Nuts, Prevailing Torque Type - Nylon Insert, Metric, Steel - BZP (Bright Zinc Plated), Grade 5, DIN 985. MPN: M4 Lock Nut N/M Insert BZP (5) Attributes: Box Quantity: 250 Driving Features: Hexagon Grade: 5 Leading Standard: DIN 985 (1987) Material: Steel Nut Type: Nylon Insert Surface Treatment: Zinc Plated Thread: Metric Thread Direction: Right Thread Size: M4