Grating Pacific
Metal Bar Grating Products
Metal Gratings Top Image
Metal Gratings Bottom Image

METAL BAR GRATINGS

Glossary


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 side of a cutout, and extending neither above nor below the bearing bars.
Load Carrying Band: A band used to transfer load between bearing bars.
Trim Band: A band which carries no load, used primarily for appearance and closing open ends.

Band
Bearing Bars – Load carrying main elements made from steel, aluminum, or stainless steel, 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 rectangular gratings, or between a bent connecting bar and a bearing bar in a riveted grating.

Cross Bars – The connecting bars which extend across the bearing bars, usually perpendicular to them. They may be bent into a corrugated or sinuous pattern 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 of combining hydraulic pressure and heat fusion to forge bearing bars and cross bars into a panel grid.

Finish – The coating, commonly 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
Flush-top Grating
by rigid attachment to cross bars running perpendicular to them or by bent connecting bars extending between them.

Hinged Panel – 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 of the letter “I”. (Commonly with a striated walking surface)
I-Bar


Length – Refer to Span of Grating

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 – Bearing bars are locked in position by cross bar deformation instead of riveting or welding. Several proven methods include:
• Expansion of an extruded or drawn tubular cross bar
• Extruded cross bar deformed or swaged between bearing bars
• Press assembly of rectangular cross bars into slotted bearing bars

Pressure Locked
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.

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 dimension of the bearing bars in this direction.

Straight Cut – Portion of the cut edge or cutout of a grating which follows a straight line.

Serrated Grating
Swaging – A method of altering the cross-section 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 the grating or tread to form a lip or curb.

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

Trim Band
– see Band

Welded Grating
– Grating in which the bearing bars and cross bars are joined at their intersections by either electro-forging or conventional hand welding.

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