Fasteners are hardware devices that either close, secure, join, or attach two or more objects together. Fasteners can either serve as temporary or permanent devices that come in varying sizes, shapes, lengths, and materials. As such, we will give a brief overview of latch and lock fasteners, two of the most common types of fasteners..
A latch is a type of fastener that engages with a
catch fasteners, keeper, or strike plate to keep an object with an entry or exit point temporarily closed. A lock is designed to withstand loosening, shock, vibration, or other dynamic forces while maintaining an entry or exit point either permanently or temporarily closed. The biggest difference between the two is the fact that a latch can keep something closed, but does not lock it.
There are a variety of lock fasteners to choose from, so ensuring you are selecting the one best suited for your application is important. Locking fasteners can be broken down into two main categories: free-running and prevailing torque. Free-running locking fasteners may or may not rely on a lock washer.
Moreover, once these fasteners have been initially loosened, they offer no further resistance to additional loosening. Prevailing torque types are designed to create friction; so, even if they become loosened, they can continue resisting any additional movements. Some common lock fasteners include turn lock fasteners, dual lock fasteners, and
slide fasteners.
Turn lock fasteners are typically used to secure inspection plates, doors, and other removable panels on aircraft. One of their most notable advantages is the ease with which they can be removed to access panels for inspection and servicing purposes.
Dual lock fasteners are positive locking, hidden fasteners that are used in a variety of attachment solutions. Moreover, they consist of strands of polyolefin stems with a mushroom shaped top.
Lastly, a slide fastener is a fastener that functions by locking together two toothed edges through the use of a sliding tab. The two parallel tracks of teeth can be interlocked or separated by pulling the sliding tab between them.
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Latch fasteners, on the other hand, vary greatly in design and complexity. One of the most common types are modern door latches. This variation of latch is called a latchbolt, or spring latch, and features a bolt with an angled end that is spring-loaded. This allows a latchbolt to retract when engaging with the strike plate and automatically extends into the strike plate once the door is closed.
Often used to secure cabinets, cam latches, or twist latches, include a cam that rotates at its base to engage and squeeze the object being fastened. Next, tension, or draw latches, feature a claw that hooks onto a catch plate and is pulled against it by a lever arm. Draw latches are typically used to secure tool boxes and cases. Lastly, an eye latch is designed with a hooked bar which grasps onto an eye mounted on the adjacent surface being fastened.