Holds things in place 50pcs / lot DIN7991 GB70.3 M3 M4 M5 M5 Hexagonal Hex Socketunk Head Allen Screw Suitable for a variety of locations : Amazon.co.uk: DIY & Tools
These little plastic washers that hold screws in place on electronics. I wanna buy them separate. I use terms like retention washer, or captive screw nut but can't find them. : r/HelpMeFind
RS PRO Cylindrical Nut For Lead Screw, Dia. 20mm | RS
Hanging by a Thread: Bolts and Screws - Stories - volumegraphics.com