I need some help with the name of a particular type of washer.
Imagine a piece of metal (say the front flap of a wall-mounted floodlight) where two bolts are used to retain the flap. Each bolt might fall but there is a washer (rubber in this case) which holds it in place.
What is the term used to described that washer?
I thought it might be called a "retaining washer" but it seems from web illustrations that retaining washers are something else.