Here are some thoughts on cold construction, they become a different way of looking at a problem..Examples are all around us free for the observant. These are some I've seen this morning.
Door hinge, nut and bolts, sewing or stitching, buttons, zippers, buckles, that thing a cabinet door that keeps it closed, o-rings, key ways, what holds the plastic nose PC on my glasses, knots, Chinese handcuffs, the container for Chinese takeout food, antique metal toys, what holds the top on a tin can or can of pop, bottle caps, magnets, how did the lead get in this pencil, or holds the eraser on, what holds that metal piece on to my Bic lighter, what keeps the strap on my watch, the hands on a clock, what keeps the knob on my air conditioner, how do these tent poles go together, how does a paint can work, what keeps a manhole cover in place, the strings on the guitar, what makes an adjustable hacksaw adjustable, the spring that closes my screen door, the latch, grommets those portable pet carriers have them all over, so does luggage, how are those metal pull chains made that hang from a lite bulb's how does a utility knife work, the latch on a garden gate, keeps a razor blade together, before post it notes were staples and paper clips, metal and wood cloths pins, mortise and tendon joints, dovetail joints, what holds the head on a hammer, how do spring rings and lobster claw clasps work, how come a head set holds on to your head, what keeps the pennies in my piggy bank, I don't have to weld a light bulb in or the battery into my flashlight, my keys are on a key ring, those pages on my spiral notebook.