... >. GB Q235qC, Q345qC (16Mnq), Q370qC, Q420qC Building Structural Steel Plate:GB Q235GJC, Q345GJC, Q390GJC, Q420GJC, Q460GJCDetails of the desingnation: Product namedesingnationdesingnation meaningexecutive standardpurposelow ... -represent the yield point;GB/T1591-94Used for engineering machinery, steel structure, Bridges, buildings, etc, and has good strength, toughness and welding ...