Abstract: A plank grating assembly for forming decking, flooring or subflooring. Longitudinal metal planks have flanges on each side edge and trapezoidal openings in each flange. The planks are rigidly connected and supported by cross braces each having an inverted V shaped configuration. Each brace is slotted at both ends. The braces can be inserted through the openings in the plank flanges and then rotated to an assembled position in which the edges of adjacent openings are closely received in the slots of the braces.