A36 steel is a common structural steel alloy utilized in the United States.[1] The A36 (UNS K02600) standard was established by the ASTM International. The standard was published in 1960 and has been updated several times since.[2] Prior to 1960, the dominant standards for structural steel in North America were A7 (until 1967[3]) and A9 (for buildings, until 1940[4]).[5] Note that SAE/AISI A7 and A9 tool steels are not the same as the obsolete ASTM A7 and A9 structural steels.

Chemical composition

Chemical composition (%, ≤) for shapes
Standard C Si Mn P S Cu
ASTM A36/A36M 0.26 0.40 1.03 0.04 0.05 0.20

Note: For shapes with a flange thickness more than 3 in (76 mm), 0.85-1.35% manganese content and 0.15-0.40% silicon content are required.


As with most steels, A36 has a density of 7,800 kg/m3 (0.28 lb/cu in). Young's modulus for A36 steel is 200 GPa.[6] A36 steel has a Poisson's ratio of 0.32 and a shear modulus of 78 GPa (11,300,000 psi).

A36 steel in plates, bars, and shapes with a thickness of less than 8 in (203 mm) has a minimum yield strength of 36,000 psi (250 MPa) and ultimate tensile strength of 58,000–80,000 psi (400–550 MPa). Plates thicker than 8 in have a 32,000 psi (220 MPa) yield strength and the same ultimate tensile strength of 58,000–80,000 psi (400–550 MPa).[1] The electrical resistance of A36 is 0.142 μΩm at 20 °C. A36 bars and shapes maintain their ultimate strength up to 650 °F (343 °C). Afterward, the minimum strength drops off from 58,000 psi (400 MPa): 54,000 psi (370 MPa) at 700 °F (371 °C); 45,000 psi (310 MPa) at 750 °F (399 °C); 37,000 psi (260 MPa) at 800 °F (427 °C).

Fabricated forms

A36 is produced in a wide variety of forms, including:

Methods of joining

A36 is readily welded by all welding processes. As a result, the most common welding methods for A36 are the cheapest and easiest: shielded metal arc welding (SMAW, or stick welding), gas metal arc welding (GMAW, or MIG welding), and oxyacetylene welding. A36 steel is also commonly bolted and riveted in structural applications. High-strength bolts have largely replaced structural steel rivets. Indeed, the latest steel construction specifications published by AISC (the 15th Edition) no longer covers their installation.

See also


  1. ^ a b Steel Construction Manual, 8th Edition, second revised edition, American Institute of Steel Construction, 1986, Ch. 1 pp. 1–5.
  2. ^ Kurt Gustafson ,Evaluation of Existing Structures, Steelwise, American Institute of Steel Construction, February 2007.
  3. ^ ASTM A7 (dead link 27 April 2023)
  4. ^ ASTM A9 dead link 27 April 2023)
  5. ^ Historical Listing of Selected Structural Steels, Canadian Institute of Steel Construction, retrieved Oct. 2021.
  6. ^ "MatWeb A36 steel bar". MatWeb. Retrieved 21 January 2012.