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 connection bars extending between them.

Bearing Bars:-

Load carrying bar made from steel strip, or slit sheet or from
rolled or extruded aluminium and extending in the direction
of the grating span.

Cross Bars:-

The connecting bars, made from steel strip, slit sheet or rolled bars,
or from rolled or extruded aluminium, which extend across the bearing bars, usually perpendicular to them.
They may be bent into a corrugated or sinuous pattern, where they interact the bearing bars which are welded to them.