Editing Handcuffs (section)

== Security ==

=== Double locks ===
Handcuffs with double locks have a detent which when engaged stops the cuff from ratcheting tighter to prevent the wearer from tightening them. Tightening could be intentional or by struggling; if tightened, the handcuffs may cause nerve damage or loss of circulation. Also some wearers could tighten the cuffs to attempt an escape by having the officer loosen the cuffs and attempting to escape while the cuffs are loose. Double locks also make picking the locks more difficult.

There exist three kinds of double locks as described in a Smith & Wesson brochure:

;Lever lock: Movement of a lever on the cuff causes the detent to move into a position that locks the bolt. No tool is required to double lock this type of cuff.
;Push pin lock: A small peg on the key is inserted endwise into a hole to engage the detent.
;Slot lock: These also are actuated with a peg, but in this case it is inserted into a slot and moved sideways to engage the detent.

Double locks are generally disengaged by inserting the key and rotating it in the opposite direction from that used to unlock the cuff.

===Keys===
[[File:CuffKey.jpg|thumb|Universal handcuff key|128x128px]]
[[File:Inmate in high security restraints (4).jpg|alt=|thumb|172x172px|An inmate in handcuffs and a belly chain with a handcuff cover, concealing the keyholes]]
Most modern handcuffs in the United States, the United Kingdom and Latin America can be opened with the same standard universal handcuff key. This allows for easier transport of prisoners. However, there are handcuff makers who use keys based on different standards. Maximum security handcuffs require special keys. Handcuff keys usually do not work with [[thumbcuffs]]. The Cuff Lock handcuff key [[padlock]] uses this same standard key.

To prevent the restrained person from eventually opening the handcuffs with a handcuff key, a [[handcuff cover]] may be used to conceal the keyholes of the handcuffs.

===Hinged and Rigid Handcuffs===
{{see also|Hiatt speedcuffs}}
When applied behind the back with keyholes away from the hands, handcuffs connected by a hinge or rigid bar are much more secure than handcuffs connected by a chain. Even with a key in hand it is difficult or impossible to reach the keyholes with it.