Qualfast: M16 Hex Slotted/Castle Nut BZP (5) Hexagon Slotted And Castle Nut Metric Steel - Grade 5 - BZP (Bright Zinc Plated) DIN 935-1 MPN: M16 Hex Slotted/Castle Nut BZP (5) Attributes: Box Quantity: 50 Dimensions P: 2 Dimensions m: 19 Dimensions n: 4.5 Dimensions s: 24 Driving Features: Hexagon Grade: 4 Material: Steel Number of Slots: 6 Supplied In: 50 Surface Treatment: Zinc Plated Thread: Metric Thread Direction: Right Thread Size: M16