PURPOSE: To make it possible to cut down the manhour of welding or the like and hold a sophisticated grating shape for a long time by constituting a grating made of cast steel which contains a specified % or below of carbon on which a letter or a figure is viewed at a lattice part, on a road surface or a floor surface.

CONSTITUTION: A grating is 350mm in outside length and 250mm in width and 18mm in thickness and has a lattice of 23 rows in the longitudinal direction and 6 rows in the lateral direction in outside dimension where a 3mm wide and 1mm deep recessed part, which is an outline of an arrow, is partially installed to the lattice of 3mm thick gratings, is manufactured with a precision casting mold which is in conformity with the shape of the grating where a JIS 304-based stainless steel is heated to 1000°C and then poured into a molding form. The composition of the SUS 304 stainless steel used herein is specified as follows: CO, 0.5 S 10.4, Mn 0.8, N 18.6 Cr 18.5 the rest Fe in weight percentage.