Posted 2 years ago
At over five inches long (without the key), this is a very large P-lock (the reason for the name is obvious); the average one is one to two inches shorter. P-locks are also known as “smokehouse” locks, “barn door” locks, etc. but of course they could have been used to secure anything with a large enough hasp. They are a type of “screw-key” lock. The bolt in a screw-key lock sits lengthwise within the cylindrical body. It engages the shackle either with a notch as this one has (pic 2) or by means of a hole in the shackle through which the bolt passes. The bolt is held in place by a spring. The opposite end of the bolt is threaded and when the key (having threads on its inside) is screwed onto the bolt it draws the bolt back allowing the shackle to swing open. The third picture shows the male threads on the bolt and female threads inside the barrel of the key. P-locks are fairly simple compared to padlocks and could have been made by any reasonably skilled blacksmith. The tiny brass P-lock in pics 1 & 2 is a fully functional 7/8” long miniature I made.