page_title: Latch
section_title: Crossbar
hierarchical_section_title: Latch / Common types / Crossbar
caption_attribution_description: Italiano: chiavistello dell'entrata di casa Magnocavallo, ad Asso
context_page_description: A latch or catch is a type of mechanical fastener that joins two objects or surfaces while allowing for their regular separation. 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.
  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.
context_section_description: A crossbar, sometimes called a bolt, is a primitive fastener consisting simply of a post barring a door.
  Crossbars were historically common, simple fasteners consisting simply of a plank or beam mounted to one side of a door by a set of cleats.  The board could be slid past the frame to block the door. Alternatively, the bar can be a separate piece that is placed into open cleats or hooks, extending across the frame on both sides. The effect of this device is essentially the opposite of the crash bar in that its operation is to permit the door to be opened inward rather than outward. On a set of double doors, the same principle works, but needn't extend past the frame. The bar simply extends into another set of cleats on the other door such as to interfere with the door opening.
caption: A crossbar on a door
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