In the case of press welded grating, it is not possible to produce very small mesh widths for technical reasons. If the customer requires the use of press welded grating but would nevertheless like to ensure that the grating is 8 mm ball proof, then this is the grating that sould be used. By welding perforated sheets with an aperture of not more than 8 mm between the bearing bars, it is possible to produce a very “close-meshed” grating for a reasonable cost. This grating corresponds to the Spanish standard no. 486/1997 (BO 23rd April 1997, no. 97/1997).