First developed around the fifth century BC, padlocks have evolved dramatically over their long and storied history, providing users with greater protection with each advance. We’ll walk you through the history of this security staple and show you how it’s been used to guard valuables for the past several thousand years.
The origins of the first padlocks are unknown, but researchers believe they first emerged in Ancient Egypt and Babylon. They’ve been in common use since at least 500 BC, when the Romans developed the oldest surviving models. Over the next several centuries, Roman traders introduced the padlock to China, where it became commonplace by the first century AD.
The materials and mechanisms used in these locks varied widely. The Roman versions were made of iron; some were fastened by a chain, while others were fastened by a spring, an attached metal pole, and a separate shackle. The Chinese versions, in contrast, were made of bronze. Several centuries later, the Viking settlers of present day York used their own version of the padlock, opened by a flat key instead of an L-shaped one.
The padlock’s popularity in England increased in the late 18th century with the rise of smokehouses, which became indispensable to food preservation. Thus the smokehouse padlock — an iron padlock with a warded keyway — rose to prominence. Slavic regions had their own competitor to the smokehouse padlock, called the screw key padlock. Elsewhere in Europe, Swedish inventor Christopher Polhem created the Scandinavian padlock, while other Scandinavian locksmiths produced the cast heart lock.
Most of these devices were rendered obsolete by the early twentieth century due to innovations in key variation and mass production. Just as importantly, the advent of modular padlocks presented a much more effective alternative. Unlike integrated padlocks, which can’t be opened or locked without a key and can’t be taken apart without breaking the locking mechanism, modular padlocks are self-locking and can be dismantled without damaging the lock itself.
The first modular padlock, created by the Yale Company, represented a major step forward in security. With pieces that could be taken apart, locks could now be serviced and rekeyed as necessary, making them much more versatile than their integrated counterparts. With the introduction of electricity and mechanized assembly lines, cheaper modular locks could soon be mass produced. They’ve been the golden standard for padlocks ever since.
Today, many different varieties of modular padlocks exist, each with different security ratings. In some models, for example, keys have been replaced by combination locks. But incredibly, the main body and shackle design, dating back millennia, have remained largely the same.