Hinges for Fire Rated Doors

Hinges for Fire Rated Doors

Fire rated door hinges are specialized, non-removable pin hinges engineered and certified to maintain the integrity of a fire door assembly during a fire event. They are a critical, code-mandated component, not a generic hardware item. These hinges are rigorously tested alongside the specific fire door and frame in recognized laboratories like UL (Underwriters Laboratories) or Intertek (Warnock Hersey) to achieve a fire protection rating, such as 20-minute, 45-minute, 60-minute, 90-minute, or 180-minute. The primary function is to ensure the door remains properly aligned and latched under intense heat, preventing the passage of flames and smoke. Standard specifications include a minimum of 3.5-inch height, a minimum of 0.180-inch ball bearing steel thickness, and the use of a non-removable pin (commonly with a set screw or allen key head) to prevent unauthorized removal of the door. Common types include ball bearing, continuous (piano) hinges, and wide throw hinges for doors with overlapping edges, all of which must bear the label of the testing agency.

According to NFPA 80 (National Fire Protection Association Standard for Fire Doors and Other Opening Protectives) and the International Building Code (IBC), fire rated hinges must be installed in a minimum quantity of two for doors up to 60 inches in height and over 60 inches require three hinges. Field data and inspection reports consistently show that the failure to use certified hinges is a leading cause of fire door violations. For instance, a standard hinge with a removable pin will deform and fail at high temperatures, causing door sag and latch failure. In contrast, tested fire rated hinges are constructed from high-grade steel with precise tolerances and specific lubricants that withstand extreme temperatures. Search results for hinge failures in fire incidents often point to the use of non-compliant hardware as a contributing factor. Manufacturers like Hager, Stanley, ASSA ABLOY (Glynn-Johnson, Corbin Russwin), and Sargent provide hinges with specific model numbers tied to their fire test listings, which must be referenced for compliance. The choice of hinge directly impacts the door's listed fire rating; substituting an unlisted hinge voids the certification. Furthermore, proper installation with all supplied screws—typically four per leaf—is essential, as missing screws reduce the hinge's load-bearing and heat resistance capacity, compromising the entire assembly's rated performance.