Hydraulic hinge Name: hydraulic hinge Type: half over lay, full over lay, small over lay Material :steel Finish: NP, AB,AC Hydraulic hingeName: hydraulic hinge Type: half over lay, full over lay, small over layMaterial :steelFinish: NP, AB,ACNickel Plated :NPAntique Brass: ABAntique Copper: AC 1. hydraulic hinge have passed 48hours salt spray test2. passed 50,000 open and closing test3. untaken ...