Hollow Metal Door Nomenclature

    Terms derived from: SDI 134-2026, click to access glossary with images.

    A

    ACTIVE DOOR:
    In a pair of doors, the door or doors in which the latching device is installed. Aslo referred to as Active Leaf.

    ADJUSTABLE FRAME: 
    A frame with profile in two or more pieces to accommodate various wall thickness. Also referred to as an Expandable Frame or Split Frame. 

    ANCHOR:
    A metal device provided inside of a jamb, head, sill or mullion used to secure the frame to the adjacent structure, such as wall, ceiling or floor. Also referred to as Jamb Anchor, Wall Anchor, Floor Anchor, etc. See listings below:

    ADJUSTABLE FLOOR ANCHOR:
    A metal device used to secure a frame to floor at base which allows the jamb to be positioned at a location in height above floor. Typically used at a depressed slab or unlevel floor condition. Also referred to as Adjustable Base Anchor.

    COMPRESSION ANCHOR:
    An adjustable metal device, used to secure, adjust and square a slip on frame.

    EXISTING WALL ANCHOR:
    A hole preparation, generally in the soffit of a frame member, with internal reinforcing and/or guide for an expansion bolt, machine bolt, or screw. Used to secure the frame to an existing opening. Also referred to as Existing Masonry Anchor.

    FIXED FLOOR ANCHOR:
    A metal device attached to the bottom of the frame to secure a frame to the floor. Also referred to as Base Anchor or Sill Anchor.

    MASONRY STRAP & STIRRUP ANCHOR:
    A fixed metal device used to secure the frame to new masonry walls.

    MASONRY “T”-SHAPED ANCHOR:
    A loose metal device used to secure the frame to new masonry walls.

    MASONRY WIRE ANCHOR:
    A loose metal device used to secure the frame to new masonry walls.

    MULLION ANCHOR:
    A metal clip or angle in either 1 or 2 pieces, secured to the floor in which mullion is then positioned over.

    SILL ANCHOR:
    A metal channel secured to the floor in which the sill section of a hollow metal frame is positioned over. Also referred to as Base Anchor.

    STEEL STUD ANCHOR:
    A metal device secured in a frame to be used for attachment to a wall built with steel studs. Also referred to as Metal Stud Anchor.

    WOOD STUD ANCHOR:
    A metal device secured in a frame to be used for attachment in a wall built with wood studs.

    APPLIED STOP:
    A separate surface mounted channel, typically used on a cased opening section. Creates a rabbeted frame profile. 

    APPLIED TRIM:
    A decorative piece mounted to the face of a frame or door. 

    ARMOR PLATE:
    A plate that can be of various materials and thicknesses applied to a door and /or frame externally, and can extend to the full height and width of the door. Not to be confused with ballistic resistance armor.

    ASTRAGAL:
    A component or combination of components applied to; (a) a single door; (b) one or both doors of a pair at their meeting stiles to cover the door edge clearance; (c) the bottom edge of the flush transom panel; or (d) the bottom of the top leaf of a dutch door. The Astragal closes the clearance gap for the purpose of ensuring privacy; minimizes the passage of light; retard the passage of air, sound, smoke or flame; and provides additional security. Provided by the hollow metal manufacturer, or the hardware supplier.

    FLAT SURFACE ASTRAGAL:
    A one-piece steel strip attached to one door and overlapping the other door when in the closed position. 

    H-ASTRAGAL:
    A formed piece of steel that caps the vertical edge of one leaf of a pair, and overlapping the other door when in the closed position.

    INTEGRAL ASTRAGAL:
    Either face of a door in a pair, formed at its lock edge to overlap the adjacent leaf. 

    Z-ASTRAGAL:
    A formed piece of steel attached to one leaf of a pair, and overlapping the other door when in the closed position. Also referred to as Wrap Around Astragal.

    B

    BACKSET:
    The distance from a cutout or datum line for a hardware preparation from a defined datumn on a door or frame.

    FLUSH BOLT BACKSET:
    The distance from the centerline of the lock edge of a door to the centerline of the bolt. Shown on beveled edge door. 

    HINGE BACKSET:
    On a door, the distance from the push side face sheet to the edge of the hinge cutout. On a frame rabbet, the distance from the stop to the edge of the hinge cutout. 

    LOCK BACKSET:
    The distance from the centerline of the lock edge of a door to the centerline of the lock face prep. Shown on beveled edge door. 

    STRIKE BACKSET:
    On a frame rabbet, the distance from the stop to the edge of the strike cutout. On the door edge, the distance from the push side face sheet to the edge of the strike cutout. 

    BELOW FLOOR:
    Below the top of the concrete or structural slab. See JAMB EXTENSION.

    BLAST RESISTANT:
    Refers to a hollow metal assembly designed and manufactured to resist a specified series of impulse pressures typically expressed in PSF. See SDI-133.

    BORROWED LIGHT:
    A glazed opening frame installed in an interior partition prepared for field installation of stationary (fixed) glazing. Mullions may be used to divide individual glazed areas. Similar to WINDOW.

    BOTTOM CHANNEL:
    The horizontal stiffener channel secured into the bottom of a door. Also referred to as end channel.

    BULL-NOSE TRIM:
    A radius shaped component applied to the vertical door edge. A typical application would be on double acting doors. 

    BULLET RESISTANT:
    A hollow metal assembly designed and manufactured to resist penetration by fire arms projectiles.

    BUTT JOINT:
    Intersection of members, which are not mitered.

    BUTTED FRAME:
    A frame which fits against a wall rather than wrapping around it.

    C

    CAMLIFT HINGE:
    A hinge designed and manufactured to provide lifting of the door to a specific height as it is opened through a specific degree of opening. Commonly used on STC door assemblies

    CEILING STRUT:
    An adjustable member extending vertically from frame to a rigid support above to hold the frame in place. 

    CLASSIFIED:
    “Products or material of a specific group category that are constructed, inspected, tested and subsequently reinspected in accordance with an established set of requirements.” (Per NFPA 80.)

    CLEARANCE:
    A term used to define a distance between two items.

    DESIGN CLEARANCE:
    The distance around a door established by the manufacturer, used to determine the Actual Door Size.

    DOOR EDGE CLEARANCE:
    The distance between either the edge of the door and frame rabbet, or the edges of two doors of a pair. 

    FLOOR CLEARANCE:
    The distance between the bottom of the door and the top of the material directly below the door. This varies with applications, such as concrete, any floor covering and/or a threshold.

    FRAME INSTALLATION, BUTTING WALL CLEARANCE:
    The distance between a frame and the wall construction where the frames butts against the wall. 

    FRAME INSTALLATION, OVERLAPPING WALL CLEARANCE:
    The distance between the frame return or backbend to accommodate irregularities in the thickness in the wall, when the frame is capping the wall. 

    OPERATING CLEARANCE:
    The final distance between door and frame after hanging and adjustment of the door and hardware.

    STOP CLEARANCE:
    The distance between the frame stop and the face of the door when the door is in the closed position. Typically equal to the thickness of the silencer or mute.

    CLOSED SECTION:
    A frame member without a throat opening such as a mullion or transom bar.

    CLOSER REINFORCEMENT:
    A metal plate or channel in a door or frame to provide additional strength for the attachment of a door closer.

    PARALLEL ARM CLOSER REINFORCEMENT:
    Reinforcing in soffit of frame header or transom mullion.

    REGULAR ARM CLOSER REINFORCEMENT:
    Reinforcing in pull side face of frame header, transom mullion, or panel.

    SLEEVE CLOSER REINFORCEMENT:
    Reinforcing inside frame header conforming to soffit, rabbet, stop, and face.

    TOP JAMB MOUNT CLOSER REINFORCEMENT:
    Reinforcing in push side face of frame header, transom mullion, or panel.

    CLOSURE CHANNEL:
    An additional channel section fitted between the flanges of the top or bottom channel of a door, with its flanges projecting inward and its web in line with the door edge.

    COMMERCIAL HOLLOW METAL:
    Steel door and frame products manufactured for use in office buildings, schools, hospitals, stores and other applications.

    COMMERCIAL SECURITY HOLLOW METAL:
    Steel door and frame products designed, tested and manufactured to resist intrusion or forced entry in commercial applications.

    COMMUNICATING FRAME:
    Hollow metal frame fabricated such that a door is installed in each rabbet of a double rabbetted frame (2 doors total) to facilitate dual access and control of the opening, i.e. hotel/motel suites, and acoustical applications. 

    COMPOSITE DOOR:
    A door consisting of a nonmetal core bonded to a metal facing.

    CONTRA-SWING FRAME:
    A frame with two doors swinging in opposite direction incorporating a fixed or removable hollow metal mullion between the doors. 

    CORE:
    The material(s) of a hollow metal door or panel.

    CORNER JOINT:
    The intersection of either the perimeter members of a metal frame product or glass stops.

    CORNER POST:
    A closed section, which facilitates a turn in the hollow metal frame assembly. The angle of the turn may vary, although 45 degree and 90 degree turns are common. Also referred to as Corner Mullion.

    COVER PLATE:
    A removable piece of metal used to cover the hardware preparation or provide access to the interior of door or frame.

    CUTOUT:
    A hole in the hollow metal door or frame to accommodate hardware, light kits, louvers or other options.

    D

    DETENTION SECURITY HOLLOW METAL:
    A steel door and frame assembly designed, tested, and manufactured for the containment of individuals to designated areas within detention or correctional facilities.

    DOOR EDGE:
    The vertical surfaces of the door.

    HINGE:
    The vertical edge of a door to which hinges or pivots are attached.

    LOCK:
    The vertical edge of a door in which locking or latching hardware may be installed.

    DOOR EDGE SEAM:
    The connection of face sheets at the vertical edge.

    CENTER SEAM:
    Door construction where door skins meet in the center of the vertical edges.

    LOCK SEAM:
    Interlocking construction of a door or panel edge.

    PAN & SKIN SEAM:
    Door construction where one skin creates a pan and the other skin overlaps creating a seam offset to one side.

    DOOR FACE:
    The exposed surface of the door not including the vertical edges and top and bottom.

    DOOR FRAME:
    An assembly of members surrounding and supporting a door, or doors.

    DOOR HARDWARE:
    The collective term for mechanical, electromechanical, and electronic devices installed on a door and/or frame that enable the door to operate, secure, control, and interface with building systems.

    CLOSER:
    A device designed to control the closing of a door from an open position, including the regulation of closing speed and latching speed. Door closers may be surface mounted, concealed, or integral to the door or frame.

    CONTINUOUS HINGE:
    A hinge extending the full height, or nearly the full height, of the door, distributing the door load along the entire edge. Continuous hinges may be surface mounted or concealed.

    CYLINDRICAL LOCK:
    A bored lockset installed through cylindrical holes in the door, incorporating a latch-bolt operated by a knob or lever. Also referred to as a Government 161 Lock or Bored Lock.

    DEAD LOCK:
    A lock utilizing a bolt that is positively projected and retracted by key or thumb-turn and is not spring-operated.

    DOOR POSITION SWITCH (DPS):
    An electrically operated switch used to monitor the open or closed position of a door.

    ELECTRIC POWER TRANSFER (EPT):
    A device used to transfer electrical power and/or signals from the door frame to the door across the hinge side, allowing electrical hardware to function without exposed wiring.

    EXIT DEVICE:

    PANIC HARDWARE: A door latching assembly incorporating an actuating member usually called an actuating bar which releases the latching or locking mechanisms upon the application of force in the direction of exit travel.

    FIRE EXIT HARDWARE: Panic Hardware which additionally provides fire protection when used as part of a fire door assembly.

    CONCEALED VERTICAL ROD EXIT DEVICE (CVR): An exit device employing vertical rods concealed within the door, engaging at one or more latching points.

    MORTISE EXIT DEVICE: Panic or Fire Exit Hardware that incorporates a mortise lock body installed in the door edge along with the actuating bar or push pad mounted on the door surface, which retracts the latch bolt mechanism housed within the mortise lock when pressure is applied.

    RIM EXIT DEVICE: A surface-mounted exit device installed on the interior face of a door, utilizing a rim latch that engages a strike mounted on the frame.

    SURFACE VERTICAL ROD EXIT DEVICE (SVR): An exit device employing surface-mounted vertical rods that engage one or more latching points.

    FLUSH BOLT:
    A manually or automatically operated bolt installed in the edge of a door, typically on the inactive leaf of a pair, that projects into the head of the and/or the floor of the opening.

    HINGE:
    A mechanical bearing device that connects a door to its frame and allows the door to pivot about a fixed axis during opening and closing. Hinges are classified by type, size, material, and performance grade.

    INTERCONNECTED LOCK:
    A mortise or bored lockset incorporating a mechanical linkage between the interior lever/ handle and all locking elements of the lock including deadlock, creating a single motion egress.

    MORTISE LOCK:
    A lock assembly installed within a mortised pocket in the edge of the door, combining latching and/or locking functions within a single case. Also referred to as a Government 86 Lock.

    OPEN BACK STRIKE:
    A strike featuring an open or extended back box to accommodate variations in door, frame, or wall conditions, allowing additional tolerance for latch projection and alignment.

    PIVOT HINGE:
    A hinge system that supports a door by means of top and bottom pivots rather than side-mounted hinges, allowing the door to rotate about a vertical axis offset from the door edge.

    STRIKE:
    A plate or assembly mounted to the door frame or inactive leaf of pair, designed to receive and support the latch-bolt, deadbolt, or exit device latch, providing proper alignment, engagement, and secure latching of the door.

    SURFACE BOLT:
    A manually operated bolt installed on the face of the door, typically on the inactive leaf of a pair, that projects into the head of the and/or the floor of the opening.

    DOOR INSET:
    The distance from the face of the door to the face of the frame on the pull side.

    DOOR LIGHT:
    The provision for glazing material in a door.

    DOOR OPENING:
    The area in a frame product into which a door or doors are installed. Measured between the rabbets horizontally and the header rabbet and bottom of frame vertically. Also referred to as Opening Size.

    DOOR OPENING HEIGHT:
    The distance measured vertically between door rabbet and the top of floor or bottom of frame minus jamb extensions. Also referred to as Nominal Door Height.

    DOOR OPENING WIDTH:
    The distance measured horizontally between door rabbets. Also referred to as Nominal Door Width. 

    DOOR REVEAL:
    The distance from the face of the door to the face of the frame on the push side.

    DOOR SCHEDULE:
    The listing of all door openings on the project by the Architect’s/Designer’ s mark number, including a description of each door opening. The schedule is normally found in the drawings or specifications.

    DOUBLE-ACTING DOOR:
    A door that swings in both directions. May incorporate bull-nose edge[s]. 

    DOUBLE-ACTING FRAME:
    A frame for double-acting doors.

    DOUBLE EGRESS DOORS:
    A pair of doors swinging in opposite directions, located in the same plane within the frame. 

    DRIP:
    A head mounted molding designed to reduce rainwater infiltration at top of door.

    DRYWALL FRAME:
    A frame designed for installation in a wall constructed with studs and gypsum wallboard or other dry sheet facing material.

    DRYWALL PROFILE:
    aAframe with backbends. Slip-on frames utilize this type of profile.

    DUTCH DOOR:
    A door consisting of two separate leaves, one above the other. May be provide with shelf at its top edge of the bottom leave. 

    DUTCH DOOR FRAME:
    A frame prepared for a dutch door.

    E

    EDGE PROFILE:
    Description of the vertical door edge; beveled, bull nosed, rabbeted, or squared, Available on lock and/or hinge edge.

    BEVELED:
    The vertical door edge has a 1/8″ in 2″ slope from a plane perpendicular to the door pull side face. 

    BULL-NOSED:
    The vertical door edge simulates a 2-1/8″ radius. 

    RABBETED:
    The vertical door edge which overlaps another door or frame. 

    SQUARED:
    The vertical door edge that is formed 90 degree to the face of the door. 

    ELECTRIC GROUT GUARD:
    A grout guard to be used with electrified hardware.

    ELEVATION:
    An orthographic projection of the vertical side of a hollow metal assembly (doors, frames, etc.) usually shown on the architectural plans in conjunction with the vertical side view of a building wall.

    EMBOSSED:
    Having a raised and/or indented pattern impressed on a surface by means of patterned rolls or stamping dies.

    F

    FIELD SPLICE:
    A means of connecting two frame sections together at the job site to create a single larger frame. Goal is to allow manufacturing, shipping, and installation greater flexibility to meet handling needs. Also referred to as Shipping Splice.

    FILLER PLATE:
    A metal plate used to fill unused mortise cutouts in a door or frame.

    FIRE PIN:
    A spring-loaded short metal rod mortised into the edge of a fire door. During a fire, when door is exposed to high temperatures, the thermal material restraining the spring-loaded pin softens or melts and the pin is released from its retracted position allowing the pin to extend into the mating receptor of the other door. Also referred to as Thermal Pin or Fusible Alignment Pin.

    FIRE RATING:
    A numeric designation indicating the duration of fire test exposure to which a product has been exposed, and successfully met all acceptance criteria of the standard to which it is tested. For swinging doors and frame products, typical fire ratings include 3, 1-1/2, 1, 3/4, and 1/3 hour. Also referred to as Fire Protection Rating.

    FIRE-RATED:
    A product which has successfully met all conditions of acceptance of the fire test standard specified in the governing model or building code, is “Listed” or “Classified” and eligible for labeling by a recognized testing agency having a factory inspection service.

    FLOOR:
    The top of the concrete or structural slab. Also referred to as Finished Floor. 

    FLOOR COVERING:
    Any material applied on top of the floor.

    FLOOR STILT:
    A metal device attached to the jamb of a door frame to hold the frame above the finished floor. 

    FLUSH DOOR:
    A door having no glass lights, panels, louvers or grilles.

    FRAME FACE:
    The elements of a frame profile which is visual on the vertical side of a hollow metal assembly. See FRAME ELEMENTS for details.

    FRAME ELEMENTS:
    Within a Frame profile, a specific part such as; soffit, stop, rabbets, faces and returns.

    BACKBEND:
    The element of the frame profile which extends from the return and is formed parallel to the wall, inside the throat. Also referred to as Second Return, Double Return or Drywall Return.

    FRAME FACE:
    The elements of a frame profile which is visual on the vertical side of a hollow metal assembly.

    JAMB DEPTH:
    The dimension of a frame member measured perpendicular to the face from one face to the other.

    RABBET:
    On a frame, the area that is between the stop and the face, capable of accepting doors, panels or glazing materials. Also referred to as Door Rabbet.

    RETURN:
    The element of the frame profile, which extends inward from the face to the throat.

    REVEAL FLANGE:
    The element of the frame profile, which extends from the return. Typically formed parallel to the wall.

    REVEAL RETURN:
    The element of the frame profile, which extends from the reveal flange.

    SOFFIT:
    The element of a door frame; (a) between the stops on a double rabbeted frame, (b) between the stop and face opposite door side of a single rabbeted frame.

    STOP:
    An element of a frame profile. Also referred to as Door Stop or Glazing Bead.

    INTEGRAL: A stop, which is formed as part of the frame profile.

    REMOVABLE: Metal channel or angle which is removable to allow installation of glass, panel or door. Also referred to as Glazing Bead.

    THROAT:
    The distance between Returns or Backbend Returns of a frame profile.

    FRAME JOINT:
    The intersection of two or more frame members.

    FRAME MEMBER:
    A component in a frame product such as a jamb, head, mullion or sill.

    HEAD:
    The horizontal member which forms the top of a frame. Also referred to as Header.

    JAMB:
    The vertical frame member forming the perimeter of a frame.

    BLANK: A jamb without mortised hardware preparation.

    HINGE: A jamb of a frame prepared for hinges or pivots.

    STRIKE: A jamb prepared for a strike.

    MULLION:
    A closed member within a frame, separating doors, a door and sidelights, glazed areas or panels. A mullion may be fixed or removable. Typically a double or single rabbeted profile.

    SILL:
    The bottom horizontal member of a sidelight or borrowed light frame. Also referred to as Base

    FRAME PRODUCTS:
    Used to describe, as a group, “Frames”, “Transom Frames”, “Sidelight Frames” and “Window Frames”.

    FRAME PROFILE:
    Visual description of a frame member.

    CASED OPENING:
    A frame without a stop and soffit.

    DOUBLE EGRESS FRAME:
    A frame prepared to receive double egress.

    DOUBLE RABBET FRAME:
    A frame provided with two rabbets.

    SINGLE RABBET FRAME:
    A frame having only one rabbet

    SLOPED PROFILE:
    A frame member where the transition from stop to opposite face is sloped. Also referred to as Hospital Profile, Splade Profile or Splayed Profile.

    FRAME SECTION:
    Cross cut of a frame member. See FRAME PROFILE.

     

    G

    GASKETING:
    Material applied around the door or frame to close the clearance opening and minimize or restrict the passage of smoke, light, sound or weather.

    GAUGE (GAGE):
    An numeric value used to define the nominal thickness of material. While the term “gauge” is no longer common for defining material thickness it is still used to specify doors and frames for ordering purposes. The term “thickness” is used when defining the actual dimension of an item, and the term “gauge” is used in the context of specifying a particular door or frame.

    GLAZING:
    A transparent material, typically glass or ceramic, installed in a door or frame.

    GLAZING BEAD:
    A removable formed metal section used to secure glazing or panel in a door or frame. Also referred to as Glass Bead.

    GLAZED LIGHT:
    In a frame, the light is formed by the assembly of jamb, head, sill and mullion members into a rectangular or shaped opening. The light is equipped with factory installed glazing bead used to retain the glazing that is installed by the glazing contractor. In a door, the light is formed by providing a rectangular or shaped cutout in the door and equipping it with molding and removable bead to receive the glazing.

    GLAZING MOLDING:
    The portion of the assembly retaining glazing materials or in-fill panels in a hollow metal door which contain the integral stop, and to which a glazing bead is attached. Also referred to as Glazing Stop.

    GLAZING MATERIAL:
    A transparent or translucent material used in door assemblies and windows. Also referred to as Glass.

    GROUT:
    A substance used to fill voids in hollow metal frame cavities. Also referred to as Mortar.

    GROUT GUARD:
    A metal cover attached to a frame behind reinforcement for mortised or recessed hardware items, to prevent grout from entering the mounting holes. Also referred to as Dust Box, Dust Cover Guard, Masonry Guard, Mortar Guard, or Plaster Guard.

    GROUTED FRAME:
    Frame filled with grout.

    H

    HANDING:
    A term used to designate the direction of door swing.

    HARDWARE SCHEDULE:
    Complete listing of all hardware specified for a project, organized by opening numbers including Door Headings, manufacturers names, template numbers, and special hardware locations. Prepared in accordance with industry standards for or by the Architect/Designer and issued for bid.

    HARDWARE TEMPLATE:
    A detailed drawing of the hardware preparation provided by hardware manufacturer for providing preparation of hardware.

    HEAD STIFFENER:
    A metal angle or channel attached inside the horizontal frame member. Not to be used as a load-carrying member.

    HINGE REINFORCEMENT:
    A metal plate or angle attached to a door or frame to which a hinge is attached.

    HOLLOW METAL:
    A term used to reference to doors, frames, partitions, enclosures and other items, fabricated from metal sheet.

    HOSPITAL STOP:
    A feature of a door frame where the stops of the door frame are terminated not more than 6 inches from the bottom of the door frame. Also referred to as Cut-Off Stop, Terminated Stop, or Sanitary Stop.

    I

    INACTIVE DOOR:
    The leaf of a pair of doors which does not contain a lock but is secured, when closed, by top and/or bottom bolts and contains a strike to receive the latch or bolt of the active leaf. Also referred to as Inactive Leaf.

    INTERGAL TAB and SLOT:
    Formed as part of the frame profile used to align machined mitered frame comer joints in mechanical alignment construction.

    INTUMESCENT SEAL:
    A strip of material fitted around a doorway, that when exposed to heat, expands closing any gaps around the door to stop the fire spreading for a period of time.

    J

    JAMB EXTENSION:
    The portion of a jamb which extends below the level of the floor. See BELOW FLOOR.

    K

    KERFED FRAME:
    A frame that is formed with an integral pocket or recess in the area of the stop to receive gasket or seals. 

    KNOCK DOWN:
    A frame product that is shipped disassembled, commonly abbreviated “KD.”

    L

    LABEL:
    A metal plate, sticker, or embossment, on a product to indicate a performance level in accordance with a specific standard.

    LAMINATED CORE:
    A door or panel construction utilizing; kraft honeycomb, rigid foam, mineral core or steel stiffeners, in which steel face sheets are bonded.

    LEADING EDGE:
    Intersection of the lock edge and the pull side face of a door.

    LEAD-LINED:
    A door or frame, which is lined with lead to prevent radiation penetration.

    LEAF:
    A single door.

    LEAVES:
    More than one door.

    LEVEL:
    Having no part higher than the other as viewed horizontally.

    LOCK CENTER CLIP:
    A part to position a mortised lock inside the center of a door.

    LOCK REINFORCEMENT:
    A plate or formed shape attached inside of a door to which a lock is fastened.

    LOUVER:
    A series of slats, blades, or piercings to allow passage of air through an opening.

    LOUVER INSERT:
    A louver that is fabricated separately and inserted into a preparation in the door or frame.

    M

    MATERIAL TYPES:

    COLD ROLLED STEEL (CRS):
    Steel that has been rolled at room temperature after hot rolling and pickling to improve surface finish, dimensional tolerances, and mechanical properties.

    HOT ROLLED STEEL (HRS):
    Steel that is rolled at elevated temperatures to facilitate forming and shaping, exhibiting wider dimensional tolerances and a scaled surface finish. Also referred to as HRS.

    GALVANIZED STEEL:
    Carbon steel that has been coated with zinc, typically by the hot-dip process, to provide corrosion resistance. Designated using “G” with the thickness of the zinc coating in ounces per square foot, i.e. G90.

    GALVANNEALED STEEL:
    Steel that has been hot-dip galvanized and annealed to produce a zinc-iron alloy coating. Designated using “A” with the thickness of the zinc coating in ounces per square foot i.e. A40 or A60.

    STAINLESS STEEL:
    A steel alloy containing a minimum of 10.5 percent chromium, which forms a passive oxide layer providing resistance to corrosion and oxidation. Designated by Type (304 & 316) and Finish Type (#2B Mill Finish, 4 Satin Brushed Finish, #6 Satin Finish, #8 Mirror Polished Finish).

    MEETING STILE:
    The vertical edge of a door, in a pair, which is adjacent to the other door.

    MITER JOINT:
    The intersection of frame members, (typically head and jambs) or frame elements (stops) in which the faces meet at an angle.

    MORTISE:
    A recess on a minimum of 3 sides of a hardware item closely surrounding the contour of the item allowing its faceplate to finish flush with the door or frame finished surface.

    MORTISE PREPARATION:
    For hardware, a cutout recessed into a door or frame, which may include, drilling and tapping.

    MUNTIN:
    A bar or formed material supporting and separating panes of glass within a door, sidelight, transom, borrowed light, or window frame. 

    N

    NAILING FLANGE:
    A reveal flange in which nail holes are provided.

    NET DOOR SIZE:
    The largest measured width by height of the door leaf as manufactured. Equal to the nominal door size minus design clearance. Also referred to as Actual Door Size.

    NOMINAL DOOR SIZE:
    (Door Opening Width) by (Door Opening Height).

    O

    OPERABLE TRANSOM:
    Panel or glass light above door opening which may be opened for ventilation purposes.

    P

    PANEL, HOLLOW METAL:
    An assembly made of the same material and construction as a door.

    PANEL, INFILL:
    An assembly comprised of steel sheet secured to each face of a backing material (gypsum or cement board, etc.), installed like glazing materials, in doors, transom, sidelight and window assemblies.

    PERIMETER FRAME JOINT:
    The intersection of two or more frame members that are accessible through the throat or from the unexposed side of the frame member.

    PLANKING:
    Wood spacers used in storage of doors and frames.

    PLINTH:
    A section of sheet metal, usually stainless steel, used as a base for a door frame at the floor. It has the same thickness and profile as the jamb section, and is flush with the jamb on all surfaces. 

    PLUMB:
    Perfectly vertical (true to a vertical plane).

    POCKET DOOR:
    A door designed to slide/recess into a wall cavity to open, and slide out of the wall cavity to close. 

    POCKET DOOR FRAME:
    Frame designed to allow a door to slide inside a pocket located within the cavity of a wall.

    PRESSURE RESISTANT:
    Refers to a hollow metal assembly designed and manufactured to resist uniform static pressure of a specified magnitude over its exposed surface.

    PRIMER / PRIME PAINT:
    Paint coating used as a base for finish paint.

    PULL SIDE OF DOOR:
    The face of a door opposite the frame stops. Also referred to as Hinge Side or Wide Side.

    PUSH SIDE OF DOOR:
    The face of door, which contacts the frame stops. Also referred to as Stop Side or Narrow Side.

    R

    RABBETED:
    Description of a door edge formed to interlock with another door, frame or panel.

    RADIATION SHIELDING:
    Refers to a hollow metal assembly designed and manufactured to resist penetration by a specified type of radiation.

    RAIL:
    The horizontal member forming the top or bottom edge of a door, or separating panels or glazed areas. Referred to as Bottom Rail, Center Rail, Intermediate Rail or Top Rail. 

    REINFORCING GUSSET:
    A flat or formed component at junction of head and jamb used in interlocking of knock-down (KD) frames. May be used as an alignment feature on punch mitered frames. Also referred to as Corner Gusset or Corner Clip.

    REMOVABLE MULLION:
    A frame member designed for temporary removal. See FRAME MEMBER, MULLION for detail.

    REVERSE BEVEL:
    Refers to hand of door or lock on outswing doors.

    ROUGH BUCK FRAME:
    An assembly which consists of a finished frame and anchoring channels. Also referred to as Sub-Buck or Sub-Frame.

    ROUGH OPENING:
    The size of the wall opening into which a frame is to be installed.

    S

    SEAMLESS DOOR:
    A door having no visible seams on its faces or edges.

    SHIM:
    Steel used to help position something by adjusting to level or filling a void.

    SHIMMING:
    The act of using a shim.

    SIDELIGHT:
    A framed area immediately aside a door opening which may contain fixed glazing, panel or other filler.

    SILENCER:
    A resilient material attached to the stop on a frame to cushion the closing of a door. Also referred to as Mute.

    SINGLE-ACTING DOOR:
    A door which only opens in one direction.

    SLIP-ON FRAME:
    Frame designed to be installed after the wall is erected.

    SMOKE CONTROL ASSEMBLY:
    A door and frame assembly with gasketing (by others) designed to resist the passage of smoke when the door is in the closed position. May or may not be fire-rated.

    SOUND TRANSMISSION CLASS (STC):
    A characteristic of a hollow metal assembly designed and manufactured to resist sound transmission. The Sound Transmission Classification (STC) rating of the assembly indicates the level of resistance to sound transmission. Also referred to as Acoustical or Sound Retardant. See SDI-128.

    SPAT:
    A protective covering, usually of stainless steel, applied over the bottom of jambs to facilitate cleaning and reduce frame damage. 

    SPREADER BAR:
    A metal channel or angle temporarily attached to the base of a door frame, extending between jambs, to keep the frame in proper alignment during shipping and handling. Also referred to as Shipping Bar.

    STIFFENER:
    An internal formed steel component used to strengthen a door panel or frame member. Also referred to as Rib.

    STILE:
    The vertical member which form the edge of a door. 

    STRIKE REINFORCEMENT:
    A metal plate or formed unit attached inside a door or frame to attach a strike.

    SURFACE HARDWARE REINFORCEMENT:
    A metal plate attached inside a door or frame to receive surface-mounted hardware applied in the field.

    SWING:
    A term used to describe the operation of a hinged door.

    SWINGING DOOR:
    A door mounted on hinges or pivots.

    T

    TEMPERATURE RISE RATED DOOR:
    A fire rated door designed to limit the transfer of heat over a specified duration to a specified temperature.

    THERMAL BOW:
    A temporary condition, affecting the operation of an exterior door due to temperature differential. The extent of this condition will vary with environmental conditions, door color, door construction, length of exposure, etc. This condition can often be alleviated by painting the outside surface of the door a light color.

    THERMAL BREAK FRAME:
    A frame with a thermal barrier or “break” to help prevent the direct transfer of heat or cold between the inside and outside portions of the frame.

    THERMAL RATED:
    Product which has been documented with a measured insulating performance value. See SDI-113.

    R-VALUE:
    The measure of thermal resistance, the higher the R-value. The more resistance the better.

    U-FACTOR:
    The measure of thermal conductivity by sampling the temperature difference of he air on both sides of the test unit. the lower the U-factor the better thermal conductivity.

    THICKNESS:
    The actual dimension of an item. See GAUGE for defining steel material.

    TOLERANCE:
    Permissible deviation from a nominal or specified dimension or value.

    TOP CHANNEL:
    Horizontal stiffener channel secured into the top of a door. Also referred to as End Channel.

    TRANSOM:
    A framed area immediately above a door opening which may containing fixed glazing, an operating sash, panel or other filler.

    TRANSOM FRAME:
    A frame containing a door opening and transom with or without a transom mullion.

    TRANSOM MULLION:
    The horizontal frame member, which separates the door opening from the transom. Also referred to as Transom Bar.

    U

    UNDERCUT:
    The Distance between the bottom of door and the bottom of the frame.

    V

    VISION LIGHT: 
    A glazed opening in a door.

    W

    WEEPHOLE:
    A opening provided to permit the drainage of moisture.

    WELD/WELDING:
    A process for the joining of metal parts, with the necessary heat being provided by an electric arc struck between an electrode and the metal or between two electrodes.

    CONTINUOUS WELD:
    A weld having no gaps or spaces, over its entire length.

    CONTINUOUSLY WELD DOOR:
    A door having all joints on its vertical edge continuously welded and finished smooth. 

    CONTINUOUSLY WELD FRAME:
    Corner/perimeter joints shall have all elements of the frame member continuously welded: soffits, stops, rabbet, faces and returns. Also called Full Weld, Fully Welded or Full Profile Welded.

    FACE WELD FRAME:
    Corner/perimeter joints shall have a continuous weld at the faces only.

    WICKET DOOR:
    A swinging door within a door.

    WINDBORN-DEBRIS IMPACT RESISTANT:
    A door, frame, or assembly that is tested and approved to withstand the impact of wind-driven debris without penetration or loss of structural integrity, and that continues to perform its intended function when subjected to subsequent wind pressures.

    WINDOW:
    A glazed opening frame installed in an exterior wall prepared for field installation stationary (fixed) glazing. Mullions may be used to divide individual glazed areas. Similar to BORROWED LIGHT.

    WRAP-AROUND FRAME:
    A frame which fits over the wall. The frame throat is nominal 1/8″ larger than the wall thickness.