wae said:Around here, sockets come in 4 common attachment sizes: ¼ inch, ⅜ inch, ½ inch, and ¾ inch.
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What nomenclature do you use to differentiate between the different sizes of sockets?
Ha ha, you got me there 
That`s one more example where we still use imperial measures. All of our metric tools have inches on the sockets. The one you mentioned, and also bigger tools with 1" ad bigger in the industry.
And as you say, I use 1/4" on small screws (M3 - M6), 3/8" on a little bigger ones (M5 - M10), and 1/2" scews/bolts/nuts from approximatley M10 and up. In really hard cases I have a 3/4" set, but it is very seldom I need that.
When it comes to the use of metric measures on inches (as accordionfolder implicates), it is widely used in plumbing and pipes. Earlier all pipes came in imperial measures, but the standards have now been converted to metric.
