Amazon.com: 2-20pcs DIN912 M3 M4 M5 M6 M8 Pure Brass Hex Hexagon Socket Cap Head Screws - (Size: M5 10pcs/ 35) SCRW-096962 : Industrial & Scientific
Amazon.com: POWERTEC QTB1006 T-Slot Bolts 1/4”-20 Thread Size T-Bolt 3.5 Inch Long – 20 Pack : Industrial & Scientific
Pack of 50 Lens Head Screws with Flange M4 x 20 mm - ISO 7380/2 - A2 Stainless Steel - Hex Socket - V2A - Lens Flange Head Screws (50, M4 x 20 mm) : Amazon.de: DIY & Tools