Door Hardware Glossary — A to Z Terminology Reference

A comprehensive glossary of door hardware terminology covering hinges, closers, locks, and related building hardware. This reference explains industry-standard terms used by architects, specifiers, contractors, and building inspectors in the door and hardware industry.

A

Active Leaf

In a pair of doors, the leaf (panel) that is primarily used for passage and which contains the latch or lock hardware. The active leaf opens and closes during normal use, while the inactive leaf is typically held stationary by flush bolts. Also called the "operating leaf."

ADA (Americans with Disabilities Act)

U.S. federal legislation enacted in 1990 that establishes accessibility requirements for buildings and facilities. For door hardware, ADA mandates a maximum opening force of 5 lbf (pounds-force) for interior doors, a minimum closing speed of 1.5 seconds from 70° open to fully closed, and lever-style handles instead of round knobs. ADA requirements apply to all public accommodations and commercial facilities.

ANSI (American National Standards Institute)

A non-profit organization that coordinates and approves voluntary consensus standards in the United States. In door hardware, ANSI standards are typically developed jointly with BHMA (Builders Hardware Manufacturers Association), resulting in ANSI/BHMA designations such as ANSI/BHMA A156.17 for self-closing hinges and pivots. See also: BHMA.

Astragal

A vertical molding or strip attached to one or both leaves of a double door to close the gap between the two leaves when the doors are shut. Astragals provide a smoke, light, and sound barrier and may be required on fire-rated door pairs to achieve the rated assembly. They can be fixed to the active leaf (overlapping astragal) or split between both leaves.

B

Backcheck

A hydraulic resistance feature in door closers and hydraulic self-closing hinges that slows the door as it approaches the fully open position (typically from about 70° to full open). Backcheck prevents doors from being thrown open violently against walls or door stops, protecting both the hardware and adjacent walls. Adjustable backcheck valves allow field tuning of the resistance level.

Ball Bearing Hinge

A hinge design that incorporates one or more ball bearings between the knuckles to reduce friction, enable smooth operation, and extend service life. Ball bearing hinges are recommended for heavy doors and high-traffic applications. They are quieter and require less maintenance than plain-bearing hinges. Most commercial-grade (ANSI/BHMA Grade 1) hinges include ball bearings as standard.

BHMA (Builders Hardware Manufacturers Association)

A trade organization representing manufacturers of builders hardware, including hinges, locks, closers, and other door hardware. BHMA develops consensus standards in collaboration with ANSI, resulting in the widely referenced ANSI/BHMA series of standards. BHMA also administers a third-party certification program to verify that products meet their stated grade and performance claims.

Butt Hinge

The most common type of door hinge, consisting of two rectangular leaves joined by a barrel and pin. Each leaf is mortised (recessed) into the edge of the door and the door frame so that the leaves sit flush with the wood or metal surfaces. Butt hinges are available in standard weight (for typical commercial applications) and heavy weight (for oversized or heavy doors). Also called a "mortise hinge." See also: Butt Hinges Guide.

C

Closer (Door Closer)

A mechanical device that controls the closing motion of a door using hydraulic or pneumatic resistance. Surface-mounted closers attach to the door face and frame with an arm linkage; concealed closers are installed inside the door or frame. Door closers are required on fire-rated doors per NFPA 80 and must meet ADA closing speed and force requirements for accessible doors. See also: Self-Closing, Hydraulic Closer.

Closing Speed

The rate at which a door travels from the open position to fully closed, measured in seconds. ADA (Americans with Disabilities Act) requires that accessible doors take a minimum of 1.5 seconds to travel from 70° open to the latch position, preventing doors from closing too quickly on individuals with disabilities. Most hydraulic closers and self-closing hinges have adjustable closing speed valves to meet this requirement.

Concealed Hinge

A hinge designed so that all mechanical components are hidden from view when the door is in the closed position. Concealed hinges are used in applications where aesthetics require clean, hardware-free door faces, such as high-end cabinetry and architectural doors. The hinge mechanism is typically mortised into the door edge and frame. See also: Concealed Hinges Guide.

Continuous Hinge

Also known as a piano hinge, a continuous hinge runs the full height of a door, distributing the door's weight and stress across the entire door height rather than concentrating it at two or three points. Continuous hinges are ideal for doors subject to heavy use or abuse, such as school lockers, gymnasium doors, and industrial applications. They provide excellent resistance to racking and sagging. See also: Continuous Hinges Guide.

Cycle Rating

The number of open-and-close cycles a hinge or closer is tested to perform without mechanical failure. Under ANSI/BHMA standards, Grade 1 self-closing hinges must complete at least 1,000,000 cycles, Grade 2 must complete 500,000 cycles, and Grade 3 must complete 250,000 cycles. Cycle ratings help specifiers match hardware durability to expected door usage in a given application.

D

Deadbolt

A lock bolt that moves into the locked position by rotating a key or thumb-turn, rather than by spring action. Deadbolts provide significantly greater security than spring latches because they cannot be retracted by applying horizontal pressure to the bolt face. Single-cylinder deadbolts are operated by key from outside and thumb-turn from inside; double-cylinder models require a key on both sides.

Door Frame

The fixed structural surround into which a door is hung. A door frame consists of two vertical members (jambs) and a horizontal member at the top (head). The frame provides the attachment point for hinges (on the hinge jamb) and the strike plate (on the strike jamb). Frames may be constructed of wood, hollow metal (steel), aluminum, or stainless steel depending on the application and fire-rating requirements.

Door Leaf

A single door panel within a door opening. A single door has one leaf; a pair of doors has two leaves (an active leaf and an inactive leaf). "Leaf" is also used to refer to one half of a hinge — each hinge has two leaves joined at the barrel. Context determines which meaning applies.

Door Stop

A device that limits how far a door can open, preventing the door from striking and damaging walls, baseboards, or other hardware. Door stops may be floor-mounted (dome or wedge style), wall-mounted (bumper style), or overhead (closer arm with built-in stop). Door stops are also the raised molding or strip on the door frame against which the door closes to form a seal. Context determines which meaning applies.

Dummy Trim

A decorative door hardware set — typically a lever or knob — that has no mechanical function. Dummy trim is used on doors that do not require a latch or lock, such as a pull-side dummy knob on a door that only opens one way, or decorative pulls on non-latching cabinet doors. Dummy trim provides visual consistency where functional hardware is not needed.

E

Edge Preparation

The machining, routing, or cutouts made to the edge of a door to accommodate mortise hardware such as locks, latches, flush bolts, and hinges. Proper edge preparation is required for hardware to sit flush with the door surface and operate correctly. Edge preparations are specified in hardware templates and must be completed before door installation.

Electrified Hardware

Door hardware that incorporates an electrical component to enable remote control, access control system integration, or fail-safe/fail-secure operation. Examples include electrified locksets, electric strikes, electromagnetic hold-open devices, and power-transfer hinges. Electrified hardware allows doors to be controlled by card readers, keypads, or building management systems.

Exit Device

Also called panic hardware or a crash bar, an exit device is a door latching assembly operated from the inside by applying pressure to a horizontal bar. Exit devices are required on egress doors in high-occupancy buildings per IBC (International Building Code) to allow rapid evacuation without knowledge of how to operate the latch. They may be rim-mounted, mortise, or concealed vertical rod style.

F

Fire Door

A door assembly — including the door, frame, hardware, and glazing — that has been tested and listed to resist the passage of fire and smoke for a specified duration, typically 20, 45, 60, 90, or 180 minutes. Fire doors are required in walls that separate different fire compartments in a building. All hardware on a fire-rated door assembly must be compatible with and tested as part of the listed assembly. See also: Fire Rating, NFPA 80.

Fire Rating

The time duration (in minutes) for which a door assembly has been tested to resist fire under standardized test conditions per NFPA 252 or UL 10C. Common fire ratings for doors are 20, 45, 60, 90, and 180 minutes. The required fire rating is determined by the fire resistance rating of the wall in which the door is installed — typically a door must be rated at a minimum of 75% of the wall's rating. All hardware on the door must carry a compatible fire rating.

Flush Bolt

A rod-type bolt installed in the edge of a door — at the top, bottom, or both — that slides into receivers in the frame head and floor to secure the inactive leaf of a door pair. Flush bolts keep the inactive leaf stationary during normal use and are required to meet positive latching requirements on fire-rated door pairs. Manual flush bolts require deliberate operation; automatic flush bolts retract when the active leaf is opened.

Frame (Door Frame)

See Door Frame.

Full Mortise

A hinge installation type in which both leaves of the hinge are recessed (mortised) into the door edge and the door frame, so the hinge sits completely flush with both surfaces. Full mortise is the standard installation for commercial butt hinges. Compare with half mortise and half surface installations.

G

Grade (ANSI/BHMA)

A performance classification for door hardware based on cycle testing, force testing, and finish durability testing per ANSI/BHMA standards. Grade 1 is the highest performance level, required for commercial and fire-rated applications. Grade 2 is mid-level, suitable for light commercial use. Grade 3 is the minimum level, typically for residential use. Only Grade 1 self-closing hinges are permitted on fire-rated door assemblies per NFPA 80.

Geared Hinge

A hinge type in which the two leaves are connected by a gear mechanism rather than a simple pin-and-barrel joint. The gear linkage synchronizes the motion of both leaves and can provide swing-clear offset functionality. Geared continuous hinges run the full height of the door and are used in high-abuse institutional applications such as prisons, schools, and hospitals.

H

Half Mortise

A hinge installation type in which one leaf is mortised into the door or frame, while the other leaf is surface-mounted on the opposing element. Half mortise is used when only one side of the installation permits routing — for example, when attaching a door to an existing metal frame where routing is not feasible.

Half Surface

A hinge installation type in which both leaves are surface-mounted — neither leaf is recessed. Half surface (also called full surface) hinges are used on hollow metal frames and in retrofit applications where creating a mortise pocket is impractical. Surface-mounted hinges are visible when the door is closed.

Hand (Handing)

The designation of which side a door is hinged on and which direction it swings, as viewed from the outside (exterior or non-secure side). "Left hand" (LH) means hinges are on the left and the door swings away from you; "right hand reverse" (RHR) means hinges are on the right and the door swings toward you. Handing is critical for specifying locks, closers, and exit devices that are not reversible in the field.

Heavy Weight Hinge

A hinge with a leaf thickness of 0.180 inches (approximately 4.6 mm), as specified in NFPA 80 Table 6.4.3.1. Heavy weight hinges are required for doors over 4 feet (1.2 m) wide or over 8 feet (2.4 m) in height on fire-rated assemblies. They provide greater strength and load capacity than standard weight hinges (0.134-inch leaf thickness). Also referred to as "heavy duty" hinges.

Hinge Pin

The cylindrical rod that passes through the interleaved knuckles of both hinge leaves to join them and serve as the pivot point for the hinge rotation. Standard hinge pins are removable by tapping upward from the bottom; non-removable pins (NRP) are staked or modified to prevent removal from the exterior side, providing added security on out-swinging exterior doors. See also: Non-Removable Pin (NRP).

Hold-Open

A feature of certain hinges and closers that allows a door to be held open at a specific angle without manual intervention. Spring hinges with a hold-open feature include a friction-based or detent mechanism that engages at a set angle (typically 90° or 105°). Note that hold-open hinges are NOT permitted on fire-rated door assemblies, which must always be self-closing per NFPA 80.

Hydraulic Closer

A door closing device that uses a hydraulic cylinder filled with oil to control closing speed through adjustable valves. Hydraulic closers provide smooth, controlled closing action with separate adjustment for latching speed and backcheck. Self-closing hinges that incorporate a hydraulic cylinder (rather than a simple spring) are sometimes called hydraulic closer hinges. See also: Hydraulic vs Spring Closing Mechanisms.

I

ICC (International Code Council)

The organization that develops and publishes the International Building Code (IBC), International Fire Code (IFC), and other model codes adopted by jurisdictions throughout the United States and internationally. ICC codes reference ANSI/BHMA, NFPA, and UL standards for door hardware requirements. See also: IBC.

IBC (International Building Code)

A model building code published by the International Code Council (ICC) that establishes minimum requirements for the design and construction of buildings and structures. The IBC specifies requirements for door hardware including panic hardware (exit devices) on high-occupancy egress doors, fire-rated door assembly requirements, and accessibility requirements referencing ICC A117.1. Most U.S. jurisdictions adopt the IBC as their base building code.

Investment Casting

A precision metal casting process in which a wax pattern of the desired part is created, coated in ceramic, and then melted out to leave a ceramic mold. Molten metal is poured into the mold to create the finished part. Investment casting produces superior dimensional accuracy, smooth surface finishes, and complex geometries compared to sand casting or die casting. Premium-grade stainless steel hinges from manufacturers such as Waterson use investment casting to achieve tighter tolerances and better corrosion resistance. See also: Investment Casting: Why the Best Hinges Are Cast, Not Stamped.

Inactive Leaf

In a pair of doors, the leaf that remains stationary during normal use. The inactive leaf is typically secured by flush bolts at the top and bottom and only opened when the full door opening width is needed. Also called the "fixed leaf" or "passive leaf." See also: Active Leaf.

J

Jamb

A vertical structural member forming the side of a door frame. Every door opening has two jambs: the hinge jamb (to which the hinges are attached) and the strike jamb (against which the latch bolt engages the strike plate). The horizontal member connecting the tops of the two jambs is called the head jamb. Jambs are constructed from wood, hollow metal, aluminum, or stainless steel depending on the application.

K

Keeper (Strike Plate)

See Strike Plate. The term "keeper" is sometimes used informally to refer to the strike plate or the box strike into which a latch bolt or deadbolt engages when a door is closed and latched.

Knuckle

The cylindrical loops or rings on each hinge leaf that interleave with each other and surround the hinge pin to form the barrel of the hinge. The number of knuckles on a hinge is related to its load capacity and smoothness of operation. A five-knuckle hinge (the most common commercial specification) has three knuckles on one leaf and two on the other. More knuckles provide greater surface contact and a smoother pivot action.

L

Latch

A spring-loaded or gravity-operated bolt that automatically engages the strike plate when a door is closed, holding the door shut without requiring a key. Latches are retracted by turning a knob, lever, or other trim to open the door. Latches alone do not provide security against forced entry; a deadbolt is needed for security. See also: Latch Bolt, Positive Latching.

Latch Bolt

The spring-loaded, beveled bolt in a lockset that automatically engages the strike plate when a door closes. The bevel allows the bolt to retract on contact with the strike plate lip and spring back into the strike opening once the door is fully closed. The latch bolt is retracted by operating the handle or lever. On fire-rated doors, the latch bolt must meet positive latching requirements to ensure the door remains securely closed against the door stop.

Leaf (Hinge)

One half of a hinge — the flat plate component that is attached to the door or the frame. Each hinge consists of two leaves: the door leaf and the frame leaf. The leaves are connected by the barrel and pin. Leaf dimensions (width and height) determine the size designation of the hinge (e.g., a 4.5" × 4.5" hinge has leaves that are 4.5 inches in each dimension when open). See also: Door Leaf.

Lever Handle

A door handle shaped as a horizontal or downward-angled lever rather than a round knob. Lever handles are required by ADA and ICC A117.1 on accessible doors because they can be operated with a closed fist or elbow, enabling use by individuals who cannot grasp a round knob. Lever handles are standard in commercial construction and available in a wide range of styles and finishes.

Listed (UL Listed)

See UL Listed. A product is "listed" when it has been evaluated and certified by a nationally recognized testing laboratory (NRTL) such as Underwriters Laboratories (UL) as meeting applicable standards. Listed status is required for hardware used in fire-rated door assemblies.

M

Mortise

A rectangular recess or pocket cut into the edge of a door or door frame to receive a hinge leaf, lock body, or other hardware so that the hardware sits flush with the surface. The process of cutting this recess is called "mortising." Full mortise hinges have both leaves recessed; half mortise hinges recess only one leaf. A mortise lock body is installed in a pocket routed into the door edge.

Mortise Lock

A lock that is installed in a rectangular pocket (mortise) cut into the door edge, as opposed to a cylindrical or bored lock that fits through drilled holes. Mortise locks offer greater strength and functionality, typically combining a latch bolt, deadbolt, and sometimes auxiliary bolts in a single unit. Mortise locksets are the standard for commercial and high-security applications.

N

NFPA (National Fire Protection Association)

A U.S.-based non-profit organization that publishes fire, electrical, and building safety codes and standards. In the door hardware industry, the most relevant NFPA publications are NFPA 80 (Standard for Fire Doors and Other Opening Protectives) and NFPA 101 (Life Safety Code). NFPA standards are widely adopted by jurisdictions as part of their building and fire codes. See also: NFPA 80.

NFPA 80

The National Fire Protection Association's Standard for Fire Doors and Other Opening Protectives. NFPA 80 governs the installation, inspection, testing, and maintenance of fire-rated door assemblies. Key hinge requirements include: minimum of one hinge per 30 inches of door height; minimum 4.5-inch hinges for commercial fire doors; heavy weight hinges for doors over 4 feet wide or 8 feet tall; and all hinges must be steel with ball bearings or anti-friction bearings. See also: NFPA 80 Fire Door Requirements.

Non-Removable Pin (NRP)

A hinge pin that has been modified — by staking, swaging, or a set screw — to prevent its removal from the hinge barrel without destroying the hinge. NRP hinges are used on out-swinging exterior doors where the hinge barrel is accessible from the exterior; without NRP treatment, a burglar could drive out the pin and remove the door from its hinges. NFPA 80 requires NRP or a similar security feature on out-swinging fire door assemblies. NRP is listed as a specification option (e.g., suffix "NRP") when ordering hinges. See also: Hinge Pin.

O

Opening Force

The force required to push or pull a door open, measured in pounds-force (lbf) or Newtons. ADA Standards for Accessible Design limit opening force to 5 lbf maximum for interior doors (excluding fire doors, which may require up to 15 lbf due to self-closing springs). Excessive opening force is a primary barrier to accessibility for individuals with disabilities and is a common code compliance issue identified during building inspections.

Overhead Concealed Closer

A door closer installed within a mortised pocket in the door and/or frame, with the mechanism hidden above the door or inside the frame head, connected to the door via a concealed pivot pin or spindle. Overhead concealed closers provide the controlled closing of a traditional surface-mounted closer while remaining invisible when the door is closed. They require precise door and frame preparation and are common in high-end architectural applications.

P

Panic Hardware

See Exit Device. The term "panic hardware" refers specifically to exit devices installed on life-safety egress doors to allow rapid, intuitive escape during emergencies. Panic hardware must be releasable with a single pushing motion on the panic bar without knowledge of the latch mechanism. Required by IBC on doors in certain occupancies including assembly rooms, educational facilities, and high-rise buildings.

Pin (Hinge Pin)

See Hinge Pin.

Pivot Hinge

A hinge mounted at the top and bottom of a door at the pivot point (not at the door edge), allowing the door to swing in both directions and providing a different swing geometry than standard butt hinges. Pivot hinges are used for heavy frameless glass doors, high-design architectural entries, and doors requiring bidirectional swing. Floor-mounted pivot hinges require a floor box installation and are more complex to install than butt hinges. See also: Pivot Hinges Guide.

Positive Latching

The requirement that a fire-rated door remain securely closed against the door stop with its latch bolt fully engaged in the strike plate when the door is in the closed position. NFPA 80 mandates positive latching on all fire door assemblies to ensure the door cannot be pushed open by fire pressure or wind. Doors without latches must use a coordinator and flush bolts or other approved positive latching means to comply.

R

Rabbet

A stepped recess cut into the edge of a door frame member, or into the meeting edge of a door pair, to provide an overlap joint. Rabbeted door frames have a built-in door stop as part of the frame profile. On door pairs, a rabbeted meeting edge on one or both leaves creates an overlapping seal between the two doors, reducing the gap and improving fire, smoke, and sound resistance. Also spelled "rebate" in British English.

Reinforcing

Additional material — typically a steel plate or channel — added to a door or frame at hardware attachment points to provide greater holding strength for screws and fasteners. Reinforcing is required in hollow metal doors at hinge, lock, and closer locations to prevent pull-through of fasteners under heavy use or impact. Hardware manufacturers specify the minimum reinforcing requirements (gauge and configuration) for proper installation of their products.

S

Self-Closing

A property of door hardware that causes the door to automatically return to the fully closed position after being opened and released. Self-closing is required by NFPA 80 on all fire-rated door assemblies to contain fire and smoke. Self-closing can be achieved with a surface-mounted door closer, a spring hinge, a hydraulic closer hinge, or an overhead concealed closer. The closing mechanism must have sufficient force to overcome carpet, weatherstripping, and other resistance to fully close and latch the door. See also: Self-Closing Hinges Guide.

Self-Latching

A property of door hardware that causes the latch bolt to automatically engage the strike plate when the door reaches the fully closed position, without any manual action by the user. Self-latching ensures that a self-closing door not only closes but also latches securely, meeting the positive latching requirement of NFPA 80 for fire-rated door assemblies. Self-latching is distinct from self-closing: a door can be self-closing without being self-latching if the latch bolt is retracted or missing.

Spring Hinge

A hinge that contains one or more coiled springs inside its barrel, providing the tension force needed to automatically close a door after it has been opened. Spring hinges are a simple and economical way to provide self-closing function without a separate door closer. ANSI/BHMA A156.17 Grade 1 spring hinges are listed for use on fire-rated door assemblies. However, spring hinges do not provide the adjustable closing speed control of hydraulic closers. See also: Spring Hinges Guide.

Standard Weight Hinge

A hinge with a leaf thickness of 0.134 inches (approximately 3.4 mm), as defined by ANSI/BHMA and NFPA 80. Standard weight hinges are appropriate for commercial doors up to 4 feet wide and 8 feet tall. Doors exceeding these dimensions on fire-rated assemblies require heavy weight hinges with 0.180-inch leaf thickness. See also: Heavy Weight Hinge.

Stainless Steel

An iron-based alloy containing a minimum of 10.5% chromium, which forms a passive oxide layer that provides corrosion resistance. In door hardware, stainless steel is specified for exterior applications, coastal environments, healthcare facilities, food service areas, and any application requiring resistance to moisture, chemicals, or harsh cleaning agents. Grade 304 stainless steel is common for indoor applications; Grade 316 provides enhanced corrosion resistance for marine or chemical environments. See also: Material Comparison Guide.

Strike Plate

A metal plate installed on the door frame strike jamb with an opening that receives the latch bolt or deadbolt when the door is closed. Strike plates reinforce the frame against the force of the latch impact and resist forced-entry attempts. Box strikes (also called lip strikes) have a deeper pocket than flat strikes, providing better bolt engagement and security. On fire-rated assemblies, the strike must be listed and compatible with the door hardware set.

Surface-Mounted

An installation method in which hardware is attached directly to the face of a door or frame without recessing into the material. Surface-mounted hinges, closers, and exit devices are more visible than mortised hardware but easier to install and replace. Surface-mounted hardware is common in commercial applications where installation speed and ease of service are priorities.

Swing Clear Hinge

An offset hinge designed so that when the door is opened to 90°, the door face swings completely clear of the door opening, maximizing the usable passage width. Swing clear hinges are used to improve ADA accessibility by providing the required 32-inch minimum clear opening width even with thick doors. The offset barrel geometry shifts the pivot point forward, moving the door out of the opening as it swings open. See also: Swing Clear Hinges Guide.

T

TAA (Trade Agreements Act)

A U.S. federal law (41 U.S.C. § 8301 et seq.) requiring that products purchased by the U.S. federal government be manufactured or substantially transformed in the United States or a designated TAA-compliant country. TAA compliance is required for door hardware specified in federal government projects and many state and local government projects. Taiwan, where Waterson manufactures its hinges, is a TAA-designated country. Products meeting this requirement are labeled "TAA Compliant."

Template Hinge

A hinge that has been manufactured with screw hole patterns conforming to industry-standard templates published by ANSI/BHMA (originally the Builders Hardware Manufacturers Association). Template holes are precisely located so that a standard door preparation can receive template hinges from any manufacturer interchangeably. Non-template hinges have random or proprietary hole patterns and may not be compatible with standard door preps. Template compliance is essential for commercial construction where doors and hardware are sourced separately.

Threshold

A transition strip or plate mounted at the bottom of a door opening, at the floor level, to bridge the gap between two floor surfaces and/or provide a seal at the base of the door. Thresholds may incorporate weatherstripping or door bottoms to seal against drafts, water, smoke, and sound. ADA requirements limit threshold height to a maximum of 0.5 inches for accessible doors, with the vertical face of any threshold over 0.25 inches required to be beveled.

U

UL (Underwriters Laboratories)

A globally recognized, independent safety certification organization that tests products and systems against established safety standards. In door hardware, UL evaluates and certifies fire-rated door assemblies (including hinges) under UL 10C (Positive Pressure Fire Tests of Door Assemblies) and UL 305 (Panic Hardware). UL-listed hardware is required for use on fire-rated door assemblies in most U.S. jurisdictions. See also: UL Fire-Rated Hinge Requirements.

UL Listed

A designation indicating that a product has been evaluated by Underwriters Laboratories and found to meet applicable UL safety standards. For door hardware, UL listing means the product has passed fire testing and is authorized for use in fire-rated door assemblies. UL maintains a published directory of listed products (the "UL Product iQ" database) that architects, inspectors, and authorities having jurisdiction (AHJ) can reference to verify listing status. See also: UL (Underwriters Laboratories).

W

Weatherstripping

Sealing material applied around the perimeter of a door — at the head, jambs, and sill — to reduce infiltration of air, water, dust, light, and sound between the door and frame. Weatherstripping materials include foam, rubber, vinyl, felt, and metal. On fire-rated door assemblies, intumescent weatherstripping expands when exposed to heat to seal the gaps between door and frame and prevent the passage of flames and hot gases. ADA-compliant doors must have weatherstripping that does not increase the door opening force beyond 5 lbf.

Wide Throw Hinge

A hinge with an extended barrel or offset leaf design that positions the door farther from the frame when open, increasing the clearance between the door face and the frame stop. Wide throw hinges are used when doors have unusually thick trim, wainscoting, or other obstructions adjacent to the frame that would prevent the door from opening a full 90° with a standard hinge. Not to be confused with swing clear hinges, which are specifically designed for ADA clear-width compliance.

Frequently Asked Questions