3/8 drive by 10mm socket with no visible markings?

[Bessy]

So while going through my carry bag this evening considering space options for sockets/ratchet, I came across this:
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a 10mm socket without a single marking on it! No ring, no etched identifier, no COO inscription, nada! Has anyone ever seen such a thing? Is this a factory mishap or just worn out inking? Keep in mind this is an old set of sockets that I think came off an old boat my dad owned for a time.

 

[blkSRT]

Looks like that one slipped pass QC

 

[Lx460]

You can never have too many 10mm sockets...

Those suckers have a way of disappearing.

 

[AceofSpad3s]

There is cheap and then there is so cheap you don't even stamp a name on it. Probably that one.

 

[malykaii]

Looks like that one slipped pass QC

I just bought a hf socket set and the 11mm is the same. Missed a step and snuck though quality control.

 

[Fedwrench]

what do the detents look like on the female square drive? Does it have those funky craftsman double detents?

Stuff happens I've gotten two of the same sized sockets, an sae mixed in with mm, more than one socket where they stamped it at the top of the socket instead of the base, and an unfinished impact socket in new sets from various makers.

 

[LB-1911]

You can never have too many 10mm sockets...

Those suckers have a way of disappearing.

And the 1st thing that goes is any sign of visible markings......