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ANCHOR – Any device used to secure a building component to adjoining construction or a supporting member. [NOMMA-86]

ANNEAL – To heat above the critical or recrystallization temperature, then cool metal, glass or other materials, to eliminate the effects of cold working, relieve internal stresses or improve electrical, magnetic or other properties; to soften. [NOMMA-86]

ANODIZE – To provide a hard non-corrosive oxide film on the surface of a metal, particularly aluminum, by electrolytic action in which the metal being treated serves as the anode. [NOMMA-86]

APPROVAL DRAWING – Drawing created to communicate the finished product to the customer. It may contain installation information not needed on a Shop Drawing. For clarity it may omit details required on the Shop Drawing.

BALUSTER – One of a series of closely spaced upright members that support the handrail in a railing. Also referred to as a Picket, Baluster Bar, Paling, Spindle, Spacer Bar, etc. [NOMMA-86]

BAR – A round, square, rectangular, hexagonal or similar section of rolled, drawn, or extruded metal. [NOMMA-86]

BASKET – A double-twisted section of two, four, or eight bars, forming a rounded open basket shape. One or more baskets are then welded to bar sections to create a single basket baluster.

BILL OF LADING – (Shipping) A written account of goods shipped by any person, signed by the agent of the owner of the carrier, acknowledging the receipt of the goods, and promising to deliver them safe at the place directed. [Webster’s] Usually there are copies of the bill for the carrier, the shipper, and the consignee of the goods.

BOTTOM RAIL – Lower member of railing system, supporting balusters or panels, if any. [NOMMA86]

BUFFING – The process of providing a lustrous finish by means of power-operated soft fabric wheels coated with a wax compound containing fine abrasive particles. [NOMMA-86]

BUILDING CODES – Building codes vary by locality. Responsibility for local code compliance rests with buyer, building owner, builder, architect, and/or engineer.

BURNISHING – Developing smooth, lustrous surface of metal part by tumbling in drum containing small steel balls or by rubbing with hard pads. [NOMMA-86]

CAP RAIL – See Handrail. [NOMMA-86]

CASTING – A product formed by pouring molten metal into a mold. [NOMMA-86]

CAST IRON – A hard, brittle, non-malleable metal that can be produced in any shape. It cannot be hammered or bent. It is used for many miscellaneous metal products. Both functional and decorative. [NOMMA-86 modified]

CHAMFER – To bevel a sharp edge. [NOMMA-86]

CHECKERED PLATE – Steel plate having a raised pattern to provide a non-slip wearing surface; referred to as “tread plate” when made of aluminum. Also called “Floor Plate” [NOMMA-86 modified]

CIRCULAR STAIR – A stair that, in plan view, has a circular form and does not have a center column. Many building codes specify the required dimensions of a circular stair. See also Spiral Stair, Curving Stair, and Winding Stair.

COLD-FINISHED STEEL – Carbon steel that has been cleaned and pickled, then rolled or drawn through dies to produce a dimensionally accurate section with improved surface finish and often other improved properties. [NOMMA-86]

COLD ROLLING – Bringing metal sheet, plate or bar to final thickness and finishing by passing between heavy rollers without heating. [NOMMA-86]

COLLAR – (1) Metal piece into which a baluster is inserted or one that encircles the baluster. Often used as an ornamental highlight in the middle portion of a plain baluster. Also refers to a band of metal that wraps around a baluster or two scrolls, etc. (2) “Collar” is also used by some as a synonym for Escutcheon. [NOMMA-86]

COMMON CARRIER – One who undertakes the office of carrying (goods or persons) for hire. Such a carrier is bound to carry in all cases when he has accommodation, and when his fixed price is tendered, and he is liable for all losses and injuries to the goods, except those which happen in consequence of the act of God, or of the enemies of the country, or of the owner of the property himself. [Webster’s]

COPE – To cut away a portion of one member, either to form a close-fitting joint with, or provide clearance for, another member. [NOMMA-86]

CORROSION – The decay of metals, usually from oxidation. [NOMMA-86]

COUNTERSINKING – Beveling end of hole for receiving conical head of flat- or oval-head fastener. [NOMMA-86]

COVER FLANGE – See Escutcheon. [NOMMA-86]

CURVING STAIR – a generic term for a stair that, in plan view, has a circular form and does not have a center column. Circular Stairs and Winding Stairs are examples of Curving Stairs for which dimensions have been defined by building codes.

DAYLIGHT DIMENSION – The amount of space between any two elements in a rail or stair design.

DELIVERY DATE – The delivery date is the date when the shipment arrives at the destination. This date depends on the carrier type and the shipment destination as related to the shipment origin.

EASEMENT (Stairs) – That curved portion of a handrail that forms a transition in a vertical plane, between a horizontal and an inclined section of the handrail. [NOMMA-86]

ELASTIC LIMIT – The maximum unit stress that can be applied to a material without causing permanent deformation. [NOMMA-86]

EMBOSSED – Having a raised and/or indented pattern impressed on one or more surfaces by means of patterned rolls, stamping dies, or hand-forging. [NOMMA-86 modified]

ESCUTCHEON – Protective or ornamental cover located usually at and around base of post or picket, baluster, or where a rail terminates against a wall. Also referred to as Cover Flange, Collar, Base, Shoe, Wall Clip or Wall Flange. [NOMMA-86]

EXTRUSION – (1) The process of producing metal shapes by forcing heated metal through an orifice in a die by means of a pressure ram. (2) Any item made by this process. [NOMMA-86]

FABRICATE – To manufacture, form, assemble or construct metal products. [NOMMA-86]

FATIGUE – Structural failure of a material caused by repeated or fluctuating application of stress, none of which individually is sufficient to cause failure. [NOMMA-861

FERROUS METAL – Metal in which iron is the principal element. [NOMMA-86]

FIELD CHECK – Verification of existing dimensions against those shown on drawing prior to fabrication. [NOMMA-86]

FIELD JOINT – A connection between two adjoining members or parts, made at the time of installation, generally accomplished by use of an internal mechanical connector or by welding. [NAAMM77]

FIELD MEASURE – Survey of existing conditions. [NOMMA-86]

FINIAL – An ornamental piece on top of railing post, newel or fence. Also referred to as Urn. [NOMMA-86]

FIXED METAL STAIR – A permanently stationary series of three or more steps in one or more flights, providing pedestrian access between different floors or levels. [NAAMM-82]

FLIGHT – An uninterrupted series of steps. [NOMMA-86]

FLIGHT RISE – The vertical distance between the floors or platforms connected by a flight of stairs. [NOMMA-86]

FLIGHT RUN – The horizontal distance between the faces of the first and last risers in a flight. [NOMMA-86]

FLOOR PLATE – See Checkered Plate.

FLOOR-TO-FLOOR HEIGHT – Dimension from the floor surface on the lower level to the floor surface of the upper level. Do not include carpet. Also known as “Finished Floor-to-Floor height”. This dimension is critical when ordering a stair.

FOB FACTORY – FOB is a shipping term meaning “Free On Board”. Freight is without charge to the purchaser for delivery on board or into a carrier at a specified point or location. [American] “FOB factory” indicates that prices and liability do not include delivery from the factory dock. At Custom Iron, our product prices are quoted as FOB Factory in Zumbrota, Minnesota. We calculate shipping to your destination and add a shipping fee to the total cost of your order.

FORGING – Heating and hammering metal into a desired shape. [NOMMA-86]

FORMING – The process of shaping metal by mechanical action other than machining, forging, or casting. [NOMMA-86]

GALVANIZING – The process of coating metal with zinc, either by dipping in a bath of molten zinc, by mechanical coating or by electrolytic action. [NOMMA-86]

GAUGE – (1) A number indicating the thickness of metal or the diameter of a wire or a fastener shank, in accordance with a standard series of numbers, each of which represents a certain decimal fraction of an inch (or number of millimeters). (2) The distance, in inches, between adjacent lines of holes or fasteners. [NOMMA-86]

GENUINE WROUGHT IRON – Low carbon content used for finer types of decorative iron works where resistance to corrosion is of value. Suppliers are somewhat limited. When Genuine Wrought Iron is specified, the words “wrought iron” are not sufficient, and this term may denote any carbon steel. Therefore, in specifying, it is important that the words “Genuine Wrought Iron” be used. Also see Wrought Iron.” [NOMMA-86]

GRINDING – Removing metal from a surface by means of abrasive action. [NOMMA-86]

HAMMERING – Hot or cold, machine or hand peening or denting of metal surfaces for artistic effect. Also referred to as Swedish Look. [NOMMA-86]

HANDRAIL – Horizontal or sloping member normally grasped by hand. This member may be part of a railing system and often, but not necessarily, top member (top rail); or may be mounted on wall or other building element. When part of stair-rail system, it is a member paralleling the pitch of the flight and is often, but not necessarily, top member. See Wall Handrail. [NOMMA-86]

HANDRAIL BRACKET – (1) A device attached to a wall, post or other surface to support a handrail. [NOMMA-86] (2) A device attached to a wall, post or other surface to support a handrail. A left-hand handrail bracket is one that is located on the users left as he ascends the stairs. A right-hand handrail bracket is one that is located on the user’s right as he ascends the stairs. [NAAMM-77]

HEADER, PLATFORM – A horizontal structural member supporting stair platform construction but carrying no stringers. [NOMMA-86]

HEADROOM – The minimum vertical distance from the top surface of a stair tread or platform to the ceiling, soffit or other overhead obstruction, measured at the outer edge of a tread. [NOMMA86]

HOT DIP GALVANIZING – The process or result of applying a protective coating to ferrous metal by dipping in a bath of molten zinc. [NOMMA-86]

HOT ROLLED – Shaped by passing a heated billet between rollers. [NOMMA-86]

HOT WORKING – The process of forming a metal when its temperature is higher than its recrystallization temperature. [NOMMA-86]

INCLINE (of stairs) – See Pitch.

I.P.S. – Iron pipe size; the nominal inside-diameter dimension of pipe. [NOMMA-86]

KNOCKED DOWN – (1) A term used in reference to any product that is shipped disassembled, for assembly at the building site; commonly abbreviated “KD”. [NOMMA-86] (2) Custom Iron ships most of its spiral stair orders KD. Assembly and installation is required at the destination. The KD shipping cost is significantly lower than shipping Set-up and the likelihood of transit damage is less.

LAMB’S TONGUE – An ornamental curved and tapered fitting terminating a handrail. [NOMMA-86]

LANDING – Level part of staircase at end of stair flight. See Platform. [NOMMA-86]

LATERAL SCROLL – A fitting that curves in a horizontal plane, used to terminate a stair handrail. Often ends up as a round plate covering the top of a post. [NOMMA-86] Also called a (horizontal) volute, particularly when made of wood.

LEAD TIME – The span of time it takes to complete an order from the order date to the shipping date. At Custom Iron, we quote lead times based on what you are planning to order. The Lead time clock starts ticking when all of the required paperwork and/or payments have been received.

MALLEABLE IRON – A sand-cast iron that is annealed and can be bent cold to some degree. It is used in many metal building products where strength and ability to resist shock are essential. It is easily welded without danger of cracking by the same method used for welding steel. [NOMMA-86]

MECHANICAL CONNECTIONS – A connection between railing members made by means other than welding or adhesive bonding. [NAAMM-77]

MID RAIL – Rail located between top and bottom rails. [NOMMA-86]

MILL FINISH – The original surface finish produced on a metal mill product by rolling, extruding, or drawing. [NOMMA-86]

MILL SCALE – The scaly oxidized surface produced on steel by heating and hot rolling. [NOMMA-86]

MOLD – A form into which molten metal is poured to produce a casting. [NOMMA-86]

NAAMM – National Association of Architectural Metal Manufacturers.

NEWEL – (1) A post member supporting the end of a stair railing or serving as a common support for two stair railings. [NOMMA-86 modified] (2) The major support posts for the balustrade system. Larger and heavier than the balusters, newels are often located at the bottom and top of a staircase and at turns and critical support areas of balcony rails. Also referred to as Main Balusters.

NON-FERROUS – Metal without any iron content. [NOMMA-86]

NOMMA – The National Ornamental & Miscellaneous Metals Association. See references for this glossary and the Custom Iron Website Links page.

NOSING – That part of a stair tread or platform which projects as a square, rounded or rounded and molded edge beyond the vertical face of the riser below it. [NOMMA-86]

ORDER DATE – The date at which all specifications, drawings, acknowledgments, and required payments have been received at Custom Iron.

PAN TREAD (Stairs) – See Tread, Pan Type. [NOMMA-86]

PANEL – (1) Custom Iron panels are balusters or sets of balusters that are welded together to create a section of balustrade. Panels can consist of scrolls, baskets, or other ornamental elements. Often used to add unique architectural interest to the railing system, panels also reduce installation time. See also Top Bar Panel. (2) Portion of railing between posts, top rail and bottom rail. [NOMMA-86]

PARALLEL STAIR – A stair consisting of flights which parallel each other and are separated only by one or more intermediate platforms. [NOMMA-86]

PICKET – One of a series of closely spaced upright members that support the handrail in a railing. See baluster. [NOMMA-86]

PICKET CASTING – Ornamental design attached to a picket. [NOMMA-86]

PICKET RAILING – Railing consisting of posts, pickets, top rail and, sometimes, bottom rail. [NOMMA-86]

PIN TOP BALUSTER – Custom Iron’s optional pin top balusters add a round peg-like extension at the ends of square bar balusters. The pin top simplifies installation into the wood stairs and handrail of the stair system.

PIPE RAILING – Railing fabricated of pipe. [NOMMA-86]

PIPE, ROUND – A hollow round section of metal, the size of which is usually designated by nominal inside diameter in inches (or millimeters). [NOMMA-86]

PITCH – The inclination or slope, measured either in degrees, percent, or by the ratio of rise to run. [NOMMA-86]

PITCH DIMENSION (Stairs) – The distance between the bases of the top and bottom risers in a flight, measured parallel to the slope. Sometimes referred to as the nose-to-nose dimension. [NOMMA-86]

PLATFORM (Stairs) – A horizontal surface usually having a dimension parallel to the stringer greater than a tread width and occurring in a stair at the end of a flight or between flights, either at a floor level or between floors. In the latter case, it is sometimes referred to as an intermediate platform or landing. [NOMMA-86 modified]

PLATFORM HEADER – See Header, Platform. [NOMMA-86]

POCKET – Opening provided in structure to accept post, rail-supporting bracket or structural member. [NOMMA-86]

POST (Railing) – A vertical, supporting member of a railing system. [NOMMA-86]

PRE-ASSEMBLED STAIR – A stair whose components are assembled in the plant to make up units of varying sizes and degrees of complexity. [NAAMM-82]

PRIMER PAINT – First coat applied to metal to retard corrosion temporarily and to provide satisfactory adhesion of finish coat. [NOMMA-86]

PUNCHING – A process of forcing a punch through the metal into a die, forming a hole in the shape of the punch. [NOMMA-86]

RAILING SYSTEM – An assembly of any of a wide selection of materials that serves as a vertical safety barrier located at the edge of a stair, platform or floor. It often supports a handrail. See Stair Rail System. [NOMMA-86 modified]

RAKE – See Pitch. [NOMMA-86]

RAKE DIMENSION – See Pitch Dimension. [NOMMA-86]

RAMP RAIL, SYSTEM – A railing system located along side(s) of ramp. [NOMMA-86]

RESTOCKING FEE – A fee charged by the seller for items that will be returned to stock. A restocking fee usually covers the seller’s cost for paperwork and handling of a returned item.

RETURN – A rail bend of 180°, as at a stair platform or railing terminal. See also Wall Return. [NAAMM-77]

RETURNED MATERIAL AUTHORIZATION (RMA) – An authorization from a manufacturer required prior to returning all or portions of an order. The RMA number given at the time the RMA is requested must appear on all returned packages.

RISE – See Flight Rise. [NOMMA-86]

RISER – The vertical or inclined face of a step, extending from the back edge of one tread to the outer edge of the tread or lower edge of the nosing next above it. [NOMMA-86]

RISER, OPEN – A term used to describe a stair having open spaces rather than risers between treads. [NOMMA-86]

RISER HEIGHT -The vertical distance between the top surfaces of two successive treads. [NOMMA86]

RUN – See Flight Run and Tread Run. [NOMMA-86]

SAND BLASTING – Subjecting to a stream of sand projected at high velocity under air or steam pressure, for the purpose of removing scale or encrusted material or to provide a textured finish. [NOMMA-86]

SCROLL – Ornamental spiral or convoluted form serving, e.g., as decorative railing panel or insert, either cast or forged. [NOMMA-86]

SET-UP – In shipping, when a product is shipped fully assembled. Usually significantly higher shipping costs than a Knocked Down shipment.

SHIP DATE – The date when an order leaves the shipping origin for transport to the shipping destination. The delivery date is the date when the shipment arrives at the destination.

SHOP DRAWING – A drawing created to communicate the finished product to the fabricator. An Approval Drawing may at times be used as a Shop Drawing.

SLAG – The crusty residue resulting from melting or welding metal. [NOMMA-86]

SLEEVE – (1) A tubular section of sheet metal or other material placed in concrete or masonry to provide either a pocket or opening for the insertion or the penetration of another item. (2) An internal tubular splice between abutting sections of pipe, tubing, or tube-like members. [NOMMA-86]

SLOPE – See pitch. [NOMMA-86]

SPECIFICATIONS – Document providing descriptive or performance requirements and criteria. [NOMMA-86]

SPINDLE – A tapered round picket, with center part larger in diameter than ends. [NOMMA-86]

SPIRAL STAIR – A stair with a closed circular form, uniform sector-shaped treads and a supporting center column. [NOMMA-86]

STAIR-RAIL SYSTEM – Railing system located along open sides of stair and landing. [NOMMA-86]

STAIR-RUN – One run of stairs between floors, platforms or floors and platforms. [NOMMA-86]

STAIRWELL – The vertical shaft space in a building occupied by a stair; also, the open well space between a series of flights. [NOMMA-86]

STEP – The combination of a riser and the tread immediately above it. [NOMMA-86]

STEP RISE – See Riser Height. [NAAMM-82]

STORY HEIGHT – The vertical distance, in a building, between one finished floor and the next.

STRAIGHT RUN STAIR – Stair extending in straight line between two floors and consisting of single flight or series of flights with one or more intermediate platforms. [NOMMA-86]

SUB-TREAD – See Tread, Pan Type. [NOMMA-86]

TEMPERING – The process of heating metal, glass or other material to temperature below transformation stage, subsequently cooling it at controlled rate to change its hardness, strength, toughness or other property. [NOMMA-86]

TEMPLATE -A pattern used as a guide. Custom Iron sometimes supplies hole placement templates for easy installation of metal railing systems.

TENSILE STRENGTH – The maximum load that can be sustained by metal in tension measured in pounds per square inch. [NOMMA-86]

TOLERANCE – Permissible deviation from a nominal or specified dimension or value. [NOMMA-86]

TOP BAR PANEL – Custom Iron’s Top Bar Panel is a framework for your balusters. The balusters that you choose are welded to a low-profile top bar that then creates a rigid section or panel. The Top Bar Panel can be easily fastened to a wood or metal handrail, rail cap or rail.

TOP RAIL – The top member of a rail system, sometimes called cap rail. [NOMMA-86]

TREAD – The horizontal member of a step. [NOMMA-86]

TREAD DEPTH – The tread run plus the projection of the nosing, if any. [NOMMA-86]

TREAD, GRATING TYPE – Tread fabricated from metal grating. [NOMMA-86]

TREAD LENGTH – The dimension of a tread measured perpendicular to the normal line of travel on a stair. [NOMMA-86]

TREAD, PAN TYPE – A tread shaped to receive a fill and provide, when filled, either a tread or a combination tread and riser. [NOMMA-86 modified]

TREAD, PLATE TYPE – A tread, or a combination of tread and riser, fabricated from metal plate, floor plate, tread plate or a combination of plates. [NOMMA-86]

TREAD RUN – The horizontal distance between two consecutive risers or, on an open riser stair, the horizontal distance between nosings or the outer edges of successive treads, all measured perpendicular to the front edges of the nosings or treads. [NOMMA-86]

TREAD WIDTH – The tread run plus the projection of the nosing, if any. [NAAMM-82]

TUBING – A hollow section of metal having a round, square, rectangular or other cross-sectional form. Size is designated by outside dimension(s) in inches or millimeters, and wall thickness in gauge number, thousandths of an inch, or millimeters, or fraction of an inch. [NOMMA-86]

VERTICAL BARRIER – A wall or railing adjacent or attached to the edge of a flight, platform or floor, to prevent persons from falling. [NAAMM-82]

VOLUTE (Stairs) – A spiral or scroll-shaped fitting used to terminate a stair handrail. [NOMMA-86]

WALL HANDRAIL – Handrail attached to wall adjacent to stair and paralleling pitch of flight, also used along walkway, ramps and corridors. Also referred to as a Wall Rail. [NOMMA-86]

WALL RETURN – A bend at the end of a wall handrail, turning it toward the wall to which it is attached. [NOMMA-86]

WELDING – The process of joining two metals or alloys by fusion. [NOMMA-86]

WINDING STAIR – A stair that, in plan view, has a circular form and does not have a center column. Many building codes specify the required dimensions of a winding stair. See also Spiral Stair, Curving Stair and Circular Stair.

WROUGHT IRON – Fabricated ornamental work, usually made of mild steel of commercial quality. Also see Genuine Wrought Iron. [NOMMA-86]


National Association of Architectural Metal Manufacturers (NAAMM). METAL STAIRS MANUAL. 1982. Fourth Edition.

National Association of Architectural Metal Manufacturers (NAAMM). PIPE RAILING MANUAL: Including Round Tube. 1977.

National Ornamental & Miscellaneous Metals Association (NOMMA). METAL RAIL MANUAL. A Guide for Architects, Designers, Fabricators, and Installers. 1986. Second Edition.

Custom Iron modifications to a NOMMA definition [NOMMA 86 – modified]

Webster’s Revised Unabridged Dictionary, © 1996, 1998

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