Qualfast: M5 Wing Nut Round Cast Iron BZP Wing Nut - Rounded Wings, Metric, Cast Iron, BZP (Bright Zinc Plated), DIN 315. MPN: M5 Wing Nut Round Cast Iron BZP Attributes: Box Quantity: 250 Driving Features: Wing Grade: 10.9 Leading Standard: DIN 315 Material: Cast Iron Surface Treatment: Zinc Plated Thread: Metric Thread Direction: Right Thread Size: M5