ASTM A709/A709M : 13

Standard Specification for Structural Steel for Bridges

Standard Details

1.1 This specification covers carbon and high-strength low-alloy steel structural shapes, plates, and bars and quenched and tempered alloy steel for structural plates intended for use in bridges. Seven grades are available in four yield strength levels as follows:

Grade U.S. [SI]	Yield Strength, ksi [MPa]
36 [250]	36 [250]
50 [345]	50 [345]
50S [345S]	50 [345]
50W [345W]	50 [345]
HPS 50W [HPS 345W]	50 [345]
HPS 70W [HPS 485W]	70 [485]
HPS 100W [HPS 690W]	100 [690]

1.1.1 Grades 36 [250], 50 [345], 50S [345S], and 50W [345W] are also included in Specifications A36/A36M, A572/A572M, A992/A992M, and A588/A588M, respectively. When the requirements of Table 8 or Table 9 or the supplementary requirements of this specification are specified, they exceed the requirements of Specifications A36/A36M, A572/A572M, A992/A992M, and A588/A588M.

1.1.2 Grades 50W [345W], HPS 50W [HPS 345W], HPS 70W [HPS 485W], and HPS 100W [HPS 690W] have enhanced atmospheric corrosion resistance (see 13.1.2). Product availability is shown in Table 1.

TABLE 1 Tensile and Hardness Requirements^A

Note 1—Where “. . .” appears in this table, there is no requirement.

Grade	Plate Thickness, in. [mm]	Structural Shape Flange or Leg Thickness, in. [mm]	Yield Point or Yield Strength,^B ksi [MPa]	Tensile Strength, ksi [MPa]	Minimum Elongation, %				Reduc- tion of Area^C^,^D min, %
					Plates and Bars^C^,^E		Shapes^E
					8 in. or 200 mm	2 in. or 50 mm	8 in. or 200 mm	2 in. or 50 mm
36 [250]	to 4 [100], incl	to 3 in. [75 mm], incl	36 [250] min	58–80 [400–550]	20	23	20	21	...
		over 3 in. [75 mm]	36 [250] min	58 [400] min	...	..	20	19	...
50 [345]	to 4 [100], incl	all	50 [345] min	65 [450] min	18	21	18	21^F	...
50S [345S]	^G	all	50–65 [345–450]^H^I	65 [450]^H min	...	...	18	21	...
50W [345W] and HPS 50W [HPS 345W]	to 4 [100], incl	all	50 [345] min	70 [485] min	18	21	18	21^J	...
HPS 70W [HPS 485 W]	to 4 [100], incl	^G	70 [485] min^B	85–110 [585–760]	...	19^K	...	...	...
HPS 100W [HPS 690W]	to 2¹/₂ [65], incl	^G	100 [690] min^B	110–130 [760–895]	...	18^K	...	...	^L
	over 2¹/₂ to 4 [65 to 100], incl^M	^G	90 [620] min^B	100–130 [690–895]	...	16^K	...	...	^L

^A See specimen orientation and preparation subsection in the Tension Tests section of Specification A6/A6M.

^B Measured at 0.2 % offset or 0.5 % extension under load as described in Section 13 of Test Methods A370.

^C Elongation and reduction of area not required to be determined for floor plates.

^D For plates wider than 24 in. [600 mm], the reduction of area requirement, where applicable, is reduced by five percentage points.

^E For plates wider than 24 in. [600 mm], the elongation requirement is reduced by two percentage points. See elongation requirement adjustments in the Tension Tests section of Specification A6/A6M.

^F Elongation in 2 in. or 50 mm: 19 % for shapes with flange thickness over 3 in. [75 mm].

^G Not applicable.

^H The yield to tensile ratio shall be 0.87 or less for shapes that are tested from the web location; for all other shapes, the requirement is 0.85.

^I A maximum yield strength of 70 ksi [480 MPa] is permitted for structural shapes that are required to be tested from the web location.

^J For wide flange shapes with flange thickness over 3 in. [75 mm], elongation in 2 in. or 50 mm of 18 % minimum applies.

^K If measured on the Fig. 3 (Test Methods A370) 1¹/₂-in. [40–mm] wide specimen, the elongation is determined in a 2-in. or 50-mm gage length that includes the fracture and shows the greatest elongation.

^L 40 % minimum applies if measured on the Fig 3 (Test Methods A370) 1¹/₂-in. [40-mm] wide specimen; 50 % minimum applies if measured on the Fig. 4 (Test Methods A370) ¹/₂-in. [12.5-mm] round specimen.

^M Not applicable to Fracture Critical Tension Components (see Table 9).

TABLE 2 Grade 36 [250] Chemical Requirements (Heat Analysis)

Note 1—Where “. . .” appears in this table there is no requirement. The heat analysis for manganese shall be determined and reported as described in the Heat Analysis section of Specification A6/A6M.

Product
Thickness,
in. (mm)

Shapes^A
All

Plate