Editing Crash bar (section)

== Latching ==
[[File:Exit_Door_Latching_Configurations.png|thumb|380x380px|Vertical rod vs center post latching]]
Crash bars offer several configurations for latching to the door frame. 

Vertical rods can be affixed to crash bars allowing both doors to be opened with no center clearance obstruction. When the bar is depressed, a chord within the vertical rod gets pulled, which lowers a latch at the top and/or bottom and allows the door to open. The ''Pullman latch'', which attaches to a Pullman keeper, is the locking mechanism usually used at the ends of the vertical rods.<ref>{{Cite web|title=What Is A Pullman Latch? » Door Hardware Genius|url=https://www.door-hardware-genius.com/?p=435|access-date=2020-06-03|language=en-US}}</ref> More expensive products may feature vertical rods and latches concealed within the door. 

[[File:Pullman_Latch_and_Keeper_Diagram.png|thumb|331x331px|Diagram of Vertical Rod Latching Elements]]
Some jurisdictions permit doors to latch to each other. For security, additional latching points may be added. For example, upper and lower vertical rods added to one door and connected to the leaf with no rods via a [[Mortise lock|mortice latch]]. A ''double door coordinator'' is used to ensure the active leaf does not close before the inactive leaf. This configuration is not recommended for high traffic locations.<ref>{{Cite web|title=Vertical Rod Panic Device - Doorware.com|url=https://www.doorware.com/specials/help-center/Vertical_Rod_Panic_Device.cfm|access-date=2020-06-03|website=www.doorware.com}}</ref>

Center posts are an alternative to vertical rods at double door exits. This offers less clearance because the post remains in the middle when both doors are open. That said, the post can often be removed with a key for occasions when items larger than a single door need to pass through. Center posts may be preferred over vertical rods because they have fewer moving parts, thus they have fewer components that can wear out or break. 

Push bars themselves are some of the most reliable door opening mechanisms. To pass CE certification, bars must function between 100,000 and 500,000 opening cycles depending on the rating the manufacturer is seeking.<ref>{{Cite web|title=Panic and Emergency Exit Hardware Introduction|url=https://www.doorhardware-online.co.uk/uploads/Exit_Hardware_Specification_Catalogue_Edit_2.pdf}}</ref>

=== Unlocking and latch hold ===
In some applications, such as storefront entrances, panic bars may be "[[Dog (engineering)|dogged]]" during business hours. Dogging is a common feature on panic bars in which the bar is retracted with a key, thus freeing the door to operate without latching. This allows customers to apply force to any portion of the door, not just the bar, in order to open it. 

Dogging is distinct from simple unlocking, which permits the user to open the door from both sides but still requires performing an action to release the latches. However, in applications where the exterior side contains an immovable ''dummy handle'', as opposed to a knob or lever handle, it is usually impossible to unlock the crash bar without also dogging it.

Dogging can extend the life of the panic bar mechanism. Some bars can be unlocked/dogged electronically, while others take a cylinder lock, [[hex key]], or contain no key functionality at all. <ref>{{Cite web|title=Exit Devices: Dogging Options|url=https://www.beaconcdl.com/exit-devices-dogging-options/|access-date=2020-06-03|language=en}}</ref> Dogging should be avoided in high wind areas where the door is susceptible to blowing open.

=== Electric strike ===
[[File:Electric_Strike_Doors.jpg|thumb|Doors with electromagnetic exit bars]]
Unlike a traditional crash bar, this type contains a horizontal touch sensor and no moving parts. When the sensor is pressed, it releases an [[electromagnetic lock]]. It may be used in tandem with a motion sensor which unlocks for anyone who stands in front of the door. This type of release must still unlock in the event of a [[power failure]], and in some jurisdictions, the door must automatically unlock for a [[fire alarm]] activation.<ref>{{Cite web|last=Greene|first=Lori|date=2017-06-20|title=Code Requirements for Electromagnetic Locks|url=https://idighardware.com/2017/06/code-requirements-for-electromagnetic-locks/|access-date=2020-06-04|website=I Dig Hardware|language=en-US}}</ref> Because these will not function in a long term power outage, they are most commonly used on secondary doors between a vestibule and the secure part of a building.

=== On automatic doors ===
In some jurisdictions, when [[Automatic door|automatic doors]] are used on the primary exit route, these doors are equipped with crash bars. In the event the automatic door does not function, it becomes an outward swinging rather than sliding door. Crash bars are one of many emergency release mechanisms that can be used with automatic doors. Depending on available space, a common alternative is to install an emergency exit door beside the automatic doors. Installation of a secondary crash bar equipped exit is often required in large buildings with revolving doors, since these are too slow for a crowd to move through.
[[File:Automatic_Door_with_Bars.jpg|thumb|Automatic sliding doors with crash bars]]