Latch (hardware)

A latch (called sneck in Northern England and Scotland) is a type of mechanical fastener that is used to join two (or more) objects or surfaces together while allowing for the regular or eventual separation of the objects or surfaces. A latch typically engages another piece of hardware on the other mounting surface. Depending upon the type and design of the latch, this engaged bit of hardware may be known as a keeper or strike. Note that a latch is not the same as the locking mechanism of a door or window, although often they are found together in the same product.

Latches range in complexity from flexible one-piece flat springs of metal or plastic, such as are used to keep blow molded plastic power tool cases closed, to multi-point cammed latches used to keep large doors closed.

A single-throw bolt. The bolt can be engaged in its strike plate only after the door is closed. The locking mechanism typically prevents the bolt from being retracted by force.

A slam latch uses a spring and is activated by the shutting or slamming of a door. Like all latches, a slam latch is a mechanism to hold a door closed. The slam latch derives its name from its ability to slam doors and drawers shut without damaging the latch. A slam latch is rugged and ideal for industrial, agricultural and construction applications.

A cam lock is a type of latch consisting of a base and a cam. The base is where the key or tool is used to rotate the cam, which is what does the latching. Cams can be straight or offset; offset cams are reversible.

A Norfolk latch is a type of latch incorporating a simple thumb-actuated lever and commonly used to hold wooden gates and doors closed. In a Norfolk latch, the handle is fitted to a backplate independently of the thumb piece. Introduced around 1800–1820, Norfolk latches, originating in the English county of the same name, differ from the older Suffolk latch, which lacked a back plate to which the thumbpiece is attached.

A Suffolk latch is a type of latch incorporating a simple thumb-actuated lever and commonly used to hold wooden gates and doors closed.

The Suffolk latch originated in the English county of Suffolk in the 16th century and stayed in common use until the 19th century. They have recently come back into favour, particularly on garden gates and sheds. They were common from the 17th century to around 1825, and their lack of a back plate made them different from the later, and neighbouring Norfolk latch (introduced 1800–1820). Both the Suffolk latch and Norfolk latch are thought to have been named by architectural draughtsman William Twopenny (1797-1873). Many of these plates found their way into America and other parts of the world.

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Wikipedia