What is this socket used for?

[dieseldodge01]

I got this socket in a big lot of sockets a bought a while back. It has a part number of 5P1763, stamped USA and is a 1/2 dr. What is this socket used for? Who made it?

 

[CouchSpring]

radiator petcock socket.

 

[flathead74]

NSN: 5120-01-128-5461
WRENCH RADIATOR SP
Mfr/OEM/Agencies: CATERPILLAR DIV GOVERNMENTAL
Suppliers: CARLTON CO
That part number comes back as a part supplied to the government by Caterpillar.

 

[dieseldodge01]

Never thought of a petcock socket. Won't have to use a channellock to open my petcocks anymore. That is a neat little history on the socket, it explains why there is no company name on the socket.

 

[wrenchr]

Just do not use it on your pet
lol