When would you double up on washers, or use spring washer for fastening?

Question

What is a good reference/handbook on practical hardware usage (tips and tricks, etc.), a lot of the time I'm guessing.

Answer 1

Double up when you need extra spacing or the s***w/bolt head is too small for the hole in the washer and you've got a second washer with a hole small enough for the head, but big enough to fit over the hole in the larger washer (if that makes sense).  Use a lock washer (I assume that's what you mean by spring) on a fastener that's subject to vibration or tension that can that cause the s***w to work it's way loose.  I prefer to use a lock washer and a flat washer together (s***w head to lock washer to flat washer to other surface, in that sequence), especially if the surface the washer is in contact with is not hard (wood, wallboard) or not flat (tubular metal).  It should work okay alone if against flat metal.  Popular Mechanics and an older mag (don't know if still in print - Home Mechanix) have many books, but don't know how your DIY interests range so can't recommend any in particluar.  Large hardware stores and most bigger bookstores stock a decent selection of DIY books.  Nowadays, I just search the web, project by project.