... C-- socket-weldingBearing bar centers:15-30, 40, 60, 80, 90 mm etc. with 30, 40 mm recommended.Cross bar ... , 100mm recommended.Surface treatment:G - galvanizedP - paintedU - untreatedGrating standard:China: YB/T4001.1-2007(YB/T4001.1-1998)Britain ... surfaceVentilation,lighting, cooling, explosion-proof, non-slip performance;Standard type: 1m×6m(special sizes are available)Material:Carbon SteelSurface ...