Vintage Snap On Socket with hole/indent

[Meursault74]

I have this vintage Snap On Socket 5/16" deep, 3/8" drive. Looks to be SFS101. There is also a hole on the outside, but not a "through hole" where the "0" would be. I looked on ebay and I didn't see other vintage ones that had this. I wonder if this was a previous owner's way of marking the tools. Anyone ever see this?

 

[chadster1]

Probably for a pinned anvil.

 

[Meursault74]

Probably for a pinned anvil.

I don't think so. There is no hole. It doesn't go all the way though. It's from the outside, maybe half the thickness deep. It's not in the right spot either, it's more toward the corner. Plus this is 5/16" socket.

Thanks for looking.

 

[Kscardsfan]

Tether point for aircraft/anti FOD situations?

 

[brownbagg]

i got some snap on sockets like that

 

[Meursault74]

So is this common with Snap On? I only have a couple random sockets made by them and this is the only one with that "feature",

 

[B_Bimmer]

I have several old ones like that.

 

[Meursault74]

I have several old ones like that.

I looked at the socket closer. I saw a "4" on it. That "style" of 4 seems to indicate the year 1984 based on a Snap On chart I saw online for their date codes.