Pin Vise-
Here's a nice assembly project that can be built using manual machine tools and hand tools.. Students and hobby machinist's will like the fact that is is not only easy to built, but also useful for holding small items. We build 30+ of these a year.....threads are single-pointed (I'm a purist) and pins press fit to one plate and clear the other (which gives me a nice chance to explain line-drilling). We buy the pins and e-ring. Penny is shown to give scale.