Difference for bridge steel materials Q345q and A709 GR 36

U.S specification ASTM A709/A709M ASME SA709/SA709M A709 GR 36 steel material and GB/T 714 Q345q steel material are both normally used building steel bridges applications.ASTM a709gr36 chemical composition is similar to steel grade Q345q,however these steel grades’gap is strength,Q345q owned a higher yield strength minimum 345Mpa and tensile strength min.490Mpa.

A709 steel materials rolled shape as A709 gr 36 steel coils,a709 gr 36 steel plates,a709 gr 36 steel sheets,a709 gr 36 angle bars,a709 gr 36 w beams,a709 gr 36 round bars,a709 gr 36 steel pipes.
 

Bridge steel grades A709GR36 vs Q345q		Chemical composition: Heat Analysis  Max%
Standard	Grade	C	Mn	P	S	Si	Cr	Ni	Cu	N
ASTM A709/A709M	A709Gr36	0.25	0.8-1.2	0.040	0.050	0.40	/	/	/	/
GB/T 714	Q345q	0.18	0.9-1.6	0.030	0.025	0.55	0.30	0.30	0.30	0.008
Mechanical Properties:		Thickness		Yield strength			Tensile strength
				Mpa  Min.			Mpa
ASTM A709/A709M	A709Gr50	T≤40		250			400-550
GB/T 714	Q345q	T≤50		345			490 min.