I bought a populated machinist's rollaway once. It has one drawer in which live a set of round "space blocks" which can be called gage blocks too. These are all the same diameter and have a central threaded hole. In that same drawer are two identical tools. These were commercially made and they were die-cast from pot metal and not finish machined at all. They are labeled' "Tommy Gage" and at one end they say "GO" and at the other they say "NO GO". I'm a reasonably savvy guy but in the 5 or so years I've owned these I still haven't figured out how to use these. They are formed in 2 halves which are threaded together with a knurled finger bolt. It seems you could somehow clamp them together with a space block to get a go/no go gage, but I can't figure out how.
Anyone know about these? I can post a picture if needed.
And yes, I've googled.
Grant Erwin Kirkland, Washington