The Coolest Lock You’ve Never Heard Of — BIR Seal Lock

This is the lock picking lawyer and today, I’m going to show you one of the coolest locks that you’ve probably never heard of it dates back to when the IRS, that is the U.S Internal Revenue Service, was known as the Bureau of internal revenue. That’S pre-1953, though. This lock is considerably older. It was produced by the now defunct sleigh maker, lock, company out of Lancaster Pennsylvania and is what’s known as a seal lock to use it.

One placed a special numbered seal behind this door, which blocks the keyway. These seals were lithographed by the U.S Bureau of Engraving and printing and were illegal to forge much like currency or postage stamps. Every month the government rotated the color of the background, the color of the lettering and the series letter that made a unique monthly combination. That would never be repeated, then, at the end of the month, users were required to destroy any leftovers, so finding intact original seals today can be challenging and finding complete sheets is something I’ve never seen before.

These were sent in by a generous viewer. Now, when this spring-loaded door is pushed aside to access the keyway, these three claws will destroy the seal, leaving unambiguous evidence of the breach. You can also see the door has a set screw to avoid accidental damage to the seal and that’s operated by this little key-shaped allen. Wrench, an additional layer of tamper resistance can be found in the fact that these locks and keys were produced exclusively for the federal government in numbered sets 20861 20861. That means Aloft couldn’t be cut apart to scavenge an intact seal.

To then put in a replacement lock. Now, because of this seal pick resistance wasn’t a huge concern, as evidenced by The Fairly rudimentary five-lever mechanism. That said, it is a little bit unique and because I don’t want to risk jamming damaging or destroying this antique, I will not attempt to pick it so overall, it was a great system, albeit probably the most expensive way, of achieving tamper resistance, though to be fair. I’D expect nothing less from the US government. In any case, that’s all I have for you today if you like this type of non-picking, lock content, please let me know in the comments.

I have lots of cool locks to share. Of course, if you want to see more of my videos, please subscribe and as always have a nice day. Thank you.