Found in a toolbox

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These keys were found at an estate sale in a toolbox belonging to someone that worked for the railroad for 40 years. We were able to identify two brass switch keys (not pictured) that were also found with these keys but we cannot figure out what these keys are. Can someone help identify these keys? The round black key has an "x" in the right corner and the stem moves back and forth (the first two pictures are the same key); there is also a hole on each side of the key. The other keys' markings are more visible in the pictures. Thanks!


What is your malfunction?
I don't know what the key is for in the first two pics, the third looks like a water faucet key with a square head, and the fourth pic is definately a RR switch lock key for the Greenleaf locks, our keys are 105's

Thanks ES and Set.

Set, what is UP (sorry, I am not a RR collector or fan yet!)?

Any clue about the black key? This is the third board I have posted these pictures on and no answers about this black key. Our curiosity is really growing! Thanks again!
Thanks Surly, the owner of this key did work for Pennsylvania before it became Conrail and worked for Conrail until his retirement in the late 1980's. One of the other brass switch keys I found is marked PCRR (not pictured).
Mystery solved!

The third key is a head hinge to an old singer machine. It is at least 50 years old!

Thanks everyone here and at the board (especially Galt!).
Agreed on the Singer hinge in pics one and two. I recognized it instantly - my mother managed a Singer sewing machine store for years and years back when I was (ahem) younger. I'm not sure about the age though. I'll leave that to further experts, but I can attest to putting a bunch of these into new sewing machine cabinets as recently as twenty years ago.

The thin legs of these hinges fit into the back of the machine and were secured with screws through the bottom if memory serves me correctly. (That's what the flat part on the leg is for). The round portion goes into a cut-out section on the top surface of the cabinet. The cabinets were designed so that the machine could be lifted up slightly, then lowered down into the cabinet, with a door folded over on top to make a flat surface for other use when the machine wasn't in use.

Thanks for sharing the pics. Sounds like some interesting finds.

The third key is used on gas or water valves. I had one like it for an aceteline bottle in a torch set. Brass is used around gas because it will not make a spark if struck against most anything and set a gas leak on fire. How big is the square hole on the end?

Larry S.
Lead Signalman, NS Ry


Been Nothin' Since Frisco
That 102 is also a Conrail key... we use those on exConrail lines.
Interesting. I suspect because they were issued to me in Texas, my 102 keys are stamped "UPRR" on the reverse side of the raised 102.

What other keys do you guys use?

I have 105 (BNSF) and Santa Fe brass keys (used on electric switches at Santa Fe yards and some older locks). I've seen 106 keys but never a 106 lock. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to