ASTM A36 Carbon Structural Steel

ASTM A36/A36M, identical with ASME SA-36/SA-36M, is the standard specification for carbon structural steel. This specification covers carbon steel shapes, plates, and bars of structural quality for use in riveted, bolted, or welded construction of bridges and buildings, and for general structural purposes. Structural products furnished under this specification shall conform to the general requirements of ASTM A6/A6M. When the ASTM A36 steel is to be welded, a suitable welding procedure shall be conducted in accordance with Appendix X6 of ASTM A6.

Specifically, the carbon structural steel products of ASTM A36 cover carbon steel beams (I beam & H beam), channels, angles, tees, bars (round, square, hexagonal, etc), flat steels, as well as other special carbon steel shapes. The steel plates can be used as bearing plates for bridges and other structures. The ASTM A36 steel shall be killed and generally it is a typical carbon steel. When necessary, a minimum of 0.20% copper shall be added to improve its corrosion resistance in damp or humid conditions. In that case, the ASTM A36 steel is a typical low alloy steel – copper steel (also known as weathering steel).

Chemical Composition Requirements

Element	Wt. %
C	≤ 0.26
*Mn	-
P	≤ 0.04
S	≤ 0.05
Si	≤ 0.40
*Cu	≥ 0.20

*Table A: chemical requirements for ASTM A36 steel shapes.
*Mn content of 0.85~1.35 % and Si content of 0.15~0.40 % is required for steel shapes with flange thickness over 3″.
*Cu content of ≥ 0.20% is required when copper steel is specified.

Item	T ≤ 0.75“	0.75" < T≤ 1.5"	1.5" < T ≤ 2.5"
C	≤0.25	≤0.25	≤0.40
Mn	-	0.80–1.20	0.80–1.20
P	≤0.030	≤0.030	≤0.030
S	≤0.030	≤0.030	≤0.030
Si	≤0.40	≤0.40	0.15–0.40
*Cu	≥0.20	≥0.20	≥0.20
Item	2.5" < T ≤ 4"	T > 4"	-
C	≤0.27	≤0.29	-
Mn	0.85–1.20	0.85–1.20	-
P	≤0.030	≤0.030	-
S	≤0.030	≤0.030	-
Si	0.15–0.40	0.15–0.40	-
*Cu	≥0.20	≥0.20	-

*Table B: chemical requirements for ASTM A36 steel plates with width above 15″ [380 mm].
*T:thickness of the plate; *Cu: when copper steel is specified; *All contents are in wt. %.

Item	T ≤ 0.75“	0.75" < T≤ 1.5"
C	≤0.26	≤0.27
Mn	-	0.60–0.90
P	≤0.04	≤0.04
S	≤0.05	≤0.05
Si	≤0.40	≤0.40
*Cu	≥0.20	≥0.20
Item	1.5" < T ≤ 4"	T > 4"
C	≤0.28	≤0.29
Mn	0.60–0.90	0.60–0.90
P	≤0.04	≤0.04
S	≤0.05	≤0.05
Si	≤0.40	≤0.40
*Cu	≥0.20	≥0.20

*Table C: chemical requirements for ASTM A36 steel plates with width ≤ 15″ [380 mm] and bars.
*T:thickness of the plate; *Cu: when copper steel is specified; *All contents are in wt. %.

For Table B and Table C, for each reduction of 0.01 percentage point below the specified carbon maximum, an increase of 0.06 percentage point manganese above the specified maximum will be permitted, up to the maximum of 1.35 %.

Mechanical Properties

*T.S. MPa [ksi]	*Y.S. MPa [ksi]	Elongation min, %
		El1	El2	El3	El4
400~550 [58~80]	≥ 250 [≥ 36]	20	23	20	21

*T.S.: tensile strength; *Y.S.: yield strength; *El₁: minimum elongation for ASTM A36 steel plates & bars in 8″ [200 mm]; *El₂: minimum elongation for ASTM A36 steel plates & bars in 2″ [50 mm]; *El₃: minimum elongation for ASTM A36 steel shapes in 8″ [200 mm]; *El₄: minimum elongation for ASTM A36 steel shapes in 2″ [50 mm]. Charpy V-Notch impact test can be performed upon customer’s request.

Other Relevant Structural Materials

In a steel structure, not only steel shapes, plates and bars, but also a plurality of other structural materials/ components shall be used to complete the construction. These relevant structural materials and their ASTM designations are listed in Table-D below. The listed components can work together with the steel products of ASTM A36 to form a steel structure.

Material	ASTM Designation
Steel rivets	A502 Gr. 1
Bolts	A307 Gr. A F568M Cl 4.6
High-strength bolts	A325
Steel nuts	A563
Cast Steel	A27
Forgings	A668
Sheets & strips	A1011 SS Gr. 36 A1018 SS Gr. 36
Hot-formed tubing	A500 Gr. B
Cold-formed tubing	A501
Anchor bolts	F1554 Gr. 36

*Table-D: other relevant materials to steel structures.