I'm putting this under construction as the parts would be part of construction--maybe wrong category.
  The Small Parts Inc company produces  and sells from others smal prts that are often difficult to get. I've had their catalog for years, it's a download on their site, and they have the most amazing things. miniature, gears, pulleys, screws of all sorts, wrenches, drills , fasteners, couplings,pivots, bearings, shaft collars  and things that can make a building job so much easier. have a look--it may prove to be useful at some point in time--I hope so.
http://www.smallparts.com

Thanks for the info Dave - that's a really useful resource.

Stuart

That's one very good site to get things from, with excellent service too. Have been using them for years. Don't know why I haven't put it onto here before. Thanks Dave for fixing my oversight.
Highly recommended
kiwi