What is the A709-50T-2 steel?

A709-50T-2 structural steel grade

Standard: ASTM A709/A709M structural steel for bridges

A709-50T-2 steel: 50 is the grade in the ASTM A709/A709M standard. The A709-50T-2 structural steel for bridges has a yield strength ≥345MPa; T: non-critical fracture tensile member. This  product used for tensile members in non-critical fracture structures ; Steel grades without T or F suffix do not need to be impact tested, but can only be used for non-tensile members or secondary members; 2 is the Charpy V-notch impact test area code, also called grade. A709-50T-2 steel for bridges is mainly used to make riveted and bolt-welded road bridges and railway bridges (including cross-sea bridges).

Chemical composition of A709-50T-2 steel

Thick, mm	max，%				Si		NB，V，or N
	C	Mn	P	S	Thick≤40	Thick>40
100	0.23	1.35	0.04	0.05	0.40	0.15-0.40	E

Note: For all steel plates with thickness> 10mm, the minimum manganese content should be 0.80% during smelting analysis, and 0.75% during product analysis;

For all steel plates with a thickness of ≤10mm and all other products, the minimum manganese content during smelting analysis should be 0.50%, and during product analysis should be 0.45%;

The difference between manganese and carbon should not be less than 2: 1. The standard stipulates that for every 0.01% reduction in the upper limit, the upper limit of manganese is allowed to increase by 0.06%, but the maximum should not exceed 1.60%.

E alloy elements are detailed in the standard sub-table.

Mechanical properties of A709-50T-2 steel

Grade	Thick, mm	Yield strength,  MPa	Tensile strength,  MPa	Elongation，Min，%
				8in[200mm]	2in[50mm]
A709-50T-2	≤100	345min	450min	18	21

A709-50T-2 steel plate thickness range: 8-100mm