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Brown-Campbell Company
Brown-Campbell Company
Specialty Steel Manufacturer,
Fabricator & Distributor Since 1952
Product Information

Introduction to Bar Grating


ANCHOR - A device by which grating is attached to its supports.

BAND - A flat bar welded to a side or 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 bars.

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

BEARING BARS - Load-carrying bars extending in the direction of the grating span.

BEARING BAR CENTERS - The distance to the center of the bearing bars.

CARRIERS (PUNCHED PLATE) - Flats 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 in a riveted grating.

CROSS RODS - The connecting bars which extend across bearing bars, perpendicular to them.

CROSS ROD CENTERS - The distance center to the 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.

FINISH - The coating, usually the paint or galvanizing, which is applied to the grating.

GRATING - An open grid assembly of metal bars, in which the bearing bars, running in one direction, are spaced by rigid cross rods attached to them.

I-BAR - An extruded aluminum bearing bar having a cross sectional shape resembling the letter ā€œIā€.

LENGTH (SPAN) - The dimension of a grating panel measured parallel to the bearing bars.

OPEN AREA PERCENTAGE - The amount of open area stated as a % of the overall size of the material. This % can vary depending on the material & manufacturing tolerances. Open area percentage can also vary depending on the manufacturing process: welded, press-locked, swaged or flush top. The open area percentages provided in this book are intended for reference only. To determine the exact open area %, the calculation must be performed for each piece of grating after it has been produced and fabricated to the finish size.

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. Usually manufactured of a checkered plate or cast aluminum abrasive material.

PRESS-LOCKED GRATING - Bearing Bars are locked in position by cross rod deformation instead of riveting or welding.

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, alternately contacting and being riveted to each.

REVERSIBLE GRATING - Grating so constructed that it may be installed either side up, with no difference in appearance or carrying capacity.

SERRATED GRATING - Grating which has the top surfaces of the bearing bars notched by punching.

SPAN OF GRATING - The distance between points of grating support, or the direction of this dimension.

STRAIGHT CUT - That portion of the cut edge or cutout of a grating which follows a straight line.

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

TOEPLATE - A flat bar attached flat against the outer edge of a grating or rear edge of a tread, and projection above the top surface of grating or tread to form a lip or curb.

TREAD - A piece of grating having carrier plates and nosing attached by welding, and designed specifically to serve as a stair tread.

WELDED GRATING - Grating in which the bearing bars and cross rods are joined at their intersections by resistance welding.

WIDTH - The overall dimension of a grating piece, measured perpendicular to the bearing bars.