The modern standard of handcuffs is the design popularized by Peerless in the early 1900’s, with few alterations since then. Most handcuff brands now bear a similar design, with only minor variances amongst the locks themselves. The design is known as a swing cuff, which features a freely swinging ratchet arm that allows law enforcement to secure the cuffs with just one hand, improving speed, agility, and safety. The most significant differences between handcuffs are found in the way the cuffs connect.
Chain handcuffs are the most widely used among law enforcement for everyday arrests due to their ease of application. The two cuffs are attached by a short chain, just one or two links long. This chain allows the cuffs to be folded in half for improved portability. The ratchet arms on chain cuffs are usually swing-through for ease and speed of application: they can be applied to the subject’s wrist with just one hand.
Hinged cuffs are very similar to chain cuffs, but they are connected with a large hinge rather than chain links. Hinged cuffs are shorter than chain cuffs when extended, which allows for less hand/arm mobility. This makes hinged cuffs potentially more secure, but somewhat more difficult to apply to a testy subject. Many law enforcement officers find that the solution to this problem, if one wrist has been cuffed but the subject is non-compliant, is the ability to apply uncomfortable torque on the cuffed wrist as a method of persuasion. The hinge adds some overall strength to the cuffs as well. Though it’s very rare, the occasional Hercules (probably somebody on drugs) may be able to snap the chain links between traditional handcuffs, but with hinged cuffs on he’s going nowhere. Like chain cuffs, hinged cuffs can be folded in half.
Solid bar handcuffs provide the same level of tamper-resistance as hinged handcuffs and even less mobility, but they come with the caveat of being harder to carry because they cannot be folded in half. Their appeal lies in the ability for an officer to apply pain-compliance techniques. Handcuffs connected with a solid bar are most likely to be used for prisoner transport of individuals who are known to be non-compliant.
Though not technically a type of handcuffs by themselves, waist chains are worth noting here for the added security they bring. The purpose of a waist chain is to further reduce a subject’s mobility. They are unable to bring their hands higher or lower than their belly, thus preventing violence and tampering.
High security handcuffs can take the form of any of the three basic types of handcuffs listed above. The primary difference is that high security handcuffs cannot be opened with a standard barrel-shaped universal handcuff key. High security handcuffs are keyed individually and are more pick-resistant than their lower security counterparts. Some high security cuffs include an additional locking position to increase the security of the double lock.
It’s impossible to trace back through history to the very first appearance of handcuff-like restraints. After all, as long as humankind has been around there has been the necessity to restrain some less-than-savory characters. Before metal handcuffs, of course, people used rope and animal hide and presumably any other strong material that would get the job done.
The first recorded mention of handcuffs appears in Virgil’s telling of the myth of Proteus, an ancient Greek shape-shifting god. According to the myth, Proteus possessed the gift of prophecy, and men desired to learn from him. But any time a human would approach and request that Proteus share his knowledge, he would shift his shape and escape. Finally Aristaeus, son of Apollo, particularly motivated by the desire to learn why his bees were dying of disease, learned (and utilized) the secret to preventing Proteus from shape shifting and escaping: handcuffs.
The first metal handcuffs as we may recognize them today came into existence with the Bronze and Iron ages, and were “one size fits all” for centuries. This lack of adjustability according to wrist size posed a serious problem: if a suspect’s wrists were too large then the cuffs were painful or simply wouldn’t close; too small and the detainee could slip right out of them. Finally, in 1862, W.V. Adams patented the first adjustable ratchet design. Orson C. Phelps followed a few years later with a patent that improved upon the original ratchet design, and beginning in 1865, John Tower (of the once industry-dominating Tower Handcuffs) used Adams’ and Phelps’ patents to manufacture what were until World War II the industry standard.
There were still problems to overcome, particularly the ease with which a suspect could shim or otherwise tamper with the lock. In 1879, Tower Handcuffs introduced the first double-locking cuff design, which effectively solved this problem by preventing the handcuffs from being ratcheted tighter, a common tactic used when shimming and otherwise attempting escape from handcuffs.
Handcuffs came closer still to the standard that we see today in 1912, when George Carney invented the first swing cuff. This design was revolutionary, as it made it possible for a law enforcement officer to quickly secure the cuffs with just one hand, greatly improving security and ease of use. The Peerless Handcuff Company, still the largest manufacturer of handcuffs today, began selling these swing cuffs, and with the exception of brand variances and small changes, the design of today’s industry standard has remained much the same. TIHK works on most Peerless-style cuffs, and has been reported to work on many other brands as well!
Take a moment to visualize a modern pair of handcuffs. In your mind’s eye, you likely see a pair of metal ratcheted cuffs attached by a short chain. Peerless Handcuff Company began manufacturing the exact cuffs that you are likely picturing in 1914, and to this day continues to lead the industry in handcuff manufacturing.
Handcuffs were revolutionized in 1912, when inventor George Carney patented the swing cuff design. Swing cuffs feature a freely swinging ratchet arm that allows law enforcement to secure the cuffs with just one hand. This was a game-changer, as officers could now cuff suspects with greatly improved speed, agility, and safety. James Milton Gill quickly purchased the patent and founded the Peerless Handcuff Company, and in 1914 began selling the first design based on Carney’s patent. The quick popularity of the swing cuff led to the obsolescence of most other designs.
Ever since, Peerless has been innovating and improving upon the standard cuff design. Along with a thinner cuff, the recognizable barrel-style key was introduced by Peerless in 1932, becoming the industry standard for universal handcuff keys. By 1978 Peerless had sold 1 million cuffs (6 million, as of 2011).
The TIHK is designed to work with most Peerless-style cuffs. When Carney’s original patent expired, nearly every other handcuff company copied the Peerless cuff design, which means there is a very wide variety of brands and styles that TIHK is likely to fit. Order now and never be caught unprepared!
There is a wide variety of ways to pick and tamper with standard handcuffs, the locks of which are operated by a rather simple mechanism. Naturally, this can cause a host of troubles for law enforcement officers, which is why the invention of the double lock by John Tower (of Tower Handcuffs, once a giant of the handcuff industry) in 1879 was revolutionary.
The double lock, which stops ratcheted handcuffs from tightening once the lock is engaged, is now a standard on most modern handcuffs, regardless of the cuff style. While the mechanism of the double lock may vary somewhat depending on manufacturer, they all serve the same two-fold purpose: to prevent potential nerve damage or loss of circulation in the event that the cuffs are tightened, and to prevent the cuffs from being picked.
The basic mechanism of a double lock involves a catch which, when engaged, checks the movement of the ratchet wheel to prevent it from tightening further. This catch is typically engaged with the blunt spike you’ll see at the end opposite the tooth on most handcuff keys, although there are also double locks that are instead engaged with a lever on the cuffs, preventing the need to fiddle with the key after cuffing the subject. The double lock is generally disengaged by rotating the universal handcuff key opposite the direction that unlocks the single lock.
A common lock-picking strategy for ratcheted cuffs is releasing the pawl with a shim. To release the pawl, a thin piece of metal is wedged between the locking mechanism and the teeth and then tightened one notch, thus unclicking the lock. This method is rendered useless with the double lock, because the ratchet will not tighten. Lock picking of every kind becomes more difficult with a double lock, because now the single lock will not release until the secondary lock has first been disengaged, even if the lock has been picked “correctly”. A subject who is unaware that the double lock has been engaged could pick at the lock for hours without success.
It’s very unlikely to come across a pair of modern handcuffs that doesn’t include a double lock; if you do, pass them up in favor of a pair that does. The double lock is one of the surest ways to prevent picking and tampering, and ensure the safety of individuals on both sides of the cuffs.
Since the invention of the highly-effective ratcheted handcuff model, patented by W.V. Adams in 1862, nearly every style of handcuffs sold has used some version of the ratchet design. The primary differences among modern handcuffs, aside from brand variances in lock design, lie in the way the two separate cuffs are connected. The three main styles of ratchet handcuffs in use today are chain cuffs, hinge cuffs, and cuffs connected with a rigid bar.
Chain cuffs are by far the most popular cuffs for everyday use in law-enforcement due to their ease of application (even on a struggling subject) and the fact that they can be folded in half for better portability. The two cuffs are attached by a short chain, typically just two links long, and the ratchet arms are usually swing-through for even greater ease and speed of application: they can be applied to the subject’s wrist with just one hand.
Hinged cuffs are very similar to chain cuffs in every capacity save the connection point: they are attached by a hinge rather than a chain. Hinge cuffs are shorter than chain cuffs when extended, thus allowing for less movement on the part of the subject. This makes them potentially more secure, but more also potentially more difficult to apply if the subject is in motion. Many law enforcement officers find that the solution to this problem, if one wrist has been cuffed but the subject is non-compliant, is the ability to apply uncomfortable torque on the cuffed wrist as a method of persuasion. This method of eliciting compliance would be difficult or impossible with the more flexible chain cuffs.
The third most common type of cuff is connected by a rigid solid bar. When actively used on a subject, they function more like hinged cuffs, holding the hands closer together than chain cuffs and providing the least mobility for the subject. This makes them more secure than chain cuffs, but the downside is that they are also more difficult to carry even than hinged cuffs because they cannot be folded in half. Rigid bar cuffs, like hinged cuffs, allow the law enforcement officer to apply pain-compliance techniques that aren’t possible with chain cuffs. Where chain cuffs are more likely to be used during an initial arrest, rigid bar cuffs may be used when transporting a subject from one place to another, particularly if the subject is known to be non-compliant.
What all of these cuffs have in common is the potential to be opened with a universal handcuff key such as TIHK. Regardless of the type of connection between the two cuffs, most modern handcuffs have a very simple lock design for practical reasons. As a result, a universal cuff key may very well be able to open chain cuffs, rigid bar cuffs, and hinged cuffs, though ease of use may vary according to the varied mobility provided by the different styles. Variations in manufacturing and lock styles notwithstanding, TIHK can open every one of these types of handcuffs.