Bridge steel plate is a thick steel plate specially used for manufacturing bridge structural parts. It is made of carbon steel and low-alloy steel for bridge construction. Carbon steel for bridge construction includes A3q for riveting bridge structures and 16q for welding bridge structures; Low alloy steels for bridge structures include 12Mnq, 12MnVq, 15MnVNq, 16Mnq, etc. The thickness of the bridge steel plate is 4.5-50 mm.

Steel plate girder bridges are a suitable bridge choice to support a variety of roadway structures, including railroad and highway traffic, so it is not surprising that they have been one of the most commonly used bridge types since the late 19th century. Steel plate girder bridges are typically used in the 100-foot to 400-foot span range. Steel plate girders consist of top and bottom flange plates that are welded to a thinner web by fillet welds. The webs will be reinforced or unreinforced.

Bridge steel plates are used to build railroad bridges, highway bridges, cross-sea bridges and so on. It is required to have high strength, toughness and to bear the load and impact of rolling stock, and to have good fatigue resistance, certain low-temperature toughness and atmospheric corrosion resistance. Tethered welding bridge steel should also have good welding performance and low notch sensitivity.