At our computer store, I had a luck to get to screw sorting (uh, how I like that) and got to question: is there any guide/rules, where should each of them be used. There are different color/material, like: silver/light-blue, quicksilver, orange/gold, black (coated?), yellow/greenish, and maybe some more. What are material properties of each? Does black coating gives anything more than look? Does black coating with gray end mean something?
There are different head caps, like: round with flat washer, round with jagged washer, round with philips, truss with philips, flanged-hex/Phillips-head combined, pan with Slot/Philips combined, flat with philips, and many more (currently counted about 70 types).
There are tapered shanks or a non-tapered shanks, and at least three different shank sizes: fine, normal and large (for FAN/Cooler mountings etc).
Most of them I have usd learning from experience, seeing "what others do". BUT, is there any good-style where each of one should be used? Maybe, there are some with better electrical conductance, good for motherboard grouding/chassis points, others are good for vibrations with breaking head base, maybe others have high durability, others are good for plastic parts, others are non rusting. I don't know, please, guide me.
Some pictures from another store: