Qualfast: 4-OCSH-40 Blind Countersunk Rivet Nut Open Serrated Shank BZP (BX-250) Blind Countersunk Rivet Nut, Open Serrated Shank, Metric, Steel, BZP ( Bright Zinc Plated). MPN: 4-OCSH-40 Blind Countersunk Rivet Nut Open Serrated Shank BZP (BX-250) Attributes: Box Quantity: 1 Drill Size: 6mm Grip range: 1.5 - 4.0mm Length: 12.5mm Material: Steel Product Type: Blind Rivet Nut Countersunk Open Shank Rivet Nut Diameter: M4 Surface Treatment: Zinc Plated