Qualfast: M4 Knurled Thumb Nut Thin A1 (50) Knurled Thumb Nuts, Metric, A1 Stainless Steel - Grade 50, DIN 467. MPN: M4 Knurled Thumb Nut Thin A1 (50) Attributes: Box Quantity: 25 Driving Features: Knurled Head Grade: 50 Leading Standard: DIN 467 Length: 4mm Material: A1 Stainless Standards Met: DIN 467 Surface Treatment: Plain System of Measurement: Metric Thread: Metric Thread Direction: Right Thread Size: M4