Bar Grating Definitions

Anchor: A device by which grating is attached to its supports.

Band: A flat bar welded to the end of a grating panel, or along the line of a cutout, and extending neither above nor below the bearing bars.

Load Carrying Band: A band used in a cutout to transfer the load from unsupported bearing bars in the cutout to the supported bearing bears.

Trim Band: A band which carries no load, but is used chiefly to improve appearance.

Bearing Bars: Load-carrying bars made from steel strip or slit sheet or from rolled or extruded aluminum and extending in the direction of the grating span.

Bearing Bar Centers: The distance center to center of the bearing bars.

Carriers: Flats or angles which are welded to the grating panel and nosing of a stair tread and are bolted to a stair stringer to support the tread.

Clear Opening: The distance between faces of bearing bars in a rectangular grating, or between a bent connecting bar and a bearing bar in a riveted grating.

Cross Bars: The connecting bars, made from steel strip, slit sheet, or rolled bars, or from rolled or extruded aluminum, which extend across the bearing bars, usually perpendicular to them. They may be bent into a corrugated or sinuous patter and, where they intersect the bearing bars, are welded, forged or mechanically locked to them.

Cross Bar Centers: The distance center to center of the cross bars.

Curved Cut: A cutout following a curved pattern.

Cutout: An area of grating removed to clear an obstruction or to permit pipes, ducts, columns, etc to pass through the grating.

Electro-Forged: A process combining hydraulic pressure and heat fusion to forge bearing bars and cross bars into a panel grid.

Finish: The coating, usually paint or galvanizing which is applied to the grating

Flush Top Grating: A type of pressure-locked grating in which the cross bars and bearing bars are in the same plane relative to the top surface of the grating.

Grating: An open grid assembly of metal bars, in which the bearing bars, running in one direction, are spaced by rigid attachment to cross bars running perpendicular to them or by bent connecting bars extending between them.

Hinged Panels: Grating panels which are hinged to their supports or to other grating parts.

I-Bar: An extruded aluminum bearing bar having a cross sectional shape resembling the letter “I”.

Length: The dimension of a grating panel measured parallel to the bearing bars. Also referred to as span.

Load-Carrying Band: see BAND.

Nosing: A special L-section member serving as the front or leading edge of a stair tread, or of grating at the head of a stair.

Pressure-Locked Grating: Grating in which the cross bars are mechanically locked to the bearing bars at their intersections by deforming or swaging the metal.

Radially Cut Grating: Rectangular grating which is cut into panels shaped as annular segments, for use in circular or annular areas.

Reticuline Bar: A sinuously bent connecting bar extending between two adjacent bearing bars, alternating contacting and being riveted to each.

Rivet Centers: The distance center to center of rivets along one bearing bar.

Riveted Grating: Grating composed of straight bearing bars and bent connecting bars, which are joined, at their contact points, by riveting.

Serrated Grating: Grating which has the top surfaces of the bearing bars or cross bars, or both, notched.

Span of Grating: The distance between points of grating support, or the direction of this dimension. Also referred to as length.

Straight Cut: That portion of the cut edge or cutout of a grating which follows a straight line.

Swaging: A method of altering the cross-sectional shape of a metal bar by pressure applied through dies.

Toe Plate: A flat bar attached against the outer edge of a grating or rear edge of a tread, and projecting above the top surface of grating or tread to form a lip or curb.

Tread: A panel of grating having carriers and nosing attached by welding, and designed specifically to serve as a stair tread.

Welded Grating: Grating in which the bearing bars and cross bars are joined at their intersections by a weld.

Width: The overall dimension of a grating panel, measured perpendicular to the bearing bars, and in the same direction as the cross bars.