This numbering system is actually quite old, in fact it even predates Snap On Wrenches, being the numbering system used by the Blue Point Wrench Company, prior to their acquisition by Snap On. That’s great! We don’t like these rapid changes..!
In case nobody had figured it out, taking Tool Mans examples again, the “OEX” part of the number refers to a combination wrench, 12 point.
An “M” suffix indicates metric, a “G” prefix industrial finish and a “W” prefix Whitworth. The numbers folks have got figured out (more or less), likewise the rest of the algebra, some of which is fairly new due to new designs like flank drive plus and ratcheting.
Some of the numbers, such as box end wrenches, are quite old, but the system starts to make more sense. An “XB” is a regular box end wrench, “XS” is short, “XO” is deep and so on. The “aerospace style” wrenches were “XD” and the current “high performance” are “XDH”. An open ender is a “VO” so if you combine the two I guess that’s how an “OEX” came about!
Once you know how the system works you can have fun confusing your dealer by asking for wrenches that don’t exist...!
Then again, with my collection, you might find that they do!