ASTM A709
ASTM A709 covers seven grades with four yield strengths intended for use in the construction of bridges. ASTM A709 includes grades covered in other ASTM specifications, including ASTM A36, A572, A588.
The American Association of State Highway and Transportation Officials (AASHTO) defines requirements for both fracture-critical (F) and non-fracture (T) critical members for structural products to be used as tension components. These requirements are written into ASTM A709. Steel grades containing a T or F suffix require impact testing; the testing temperature is determined by the service temperature zone.
ASTM A709 uses letter suffixes to denote corrosion resistance. No suffix (ex: Grade 36) indicates typical carbon or alloy steel without improved corrosion resistance. A “W” suffix indicates improved atmospheric corrosion resistance.
Available Designations
High-Strength Low Alloy Steel (HSLAS): furnished to a chemical composition and defined mechanical properties. HSLA steels contain strengthening microalloys (niobium, vanadium, titanium) singly or in combination.
Structural Steel: ASTM A709 includes ASTM A36 carbon structural steel, and quenched and tempered alloy steel.
Structural Steel: ASTM A709 includes ASTM A36 carbon structural steel, and quenched and tempered alloy steel.
Listed Designations
Comparable to A36
Types A and B, equivalent to A588 Grades A and B
^ Yield strength, tensile strength, and elongation guaranteed in the transverse direction.
ASTM A709 Characteristics
Property
specification
Weldability
Increased carbon content is associated with increased hardenability, leading to the risk of cracking after welding.
Steel Warehouse can limit carbon contents to improve thermal cutting, formability, and welding performance.
Ease of Fabrication
ASTM A709 covers a wide range of steel products with varying chemical contents, mechanical properties, and thermal treatments. For specific inquiries, please use the Ask an Expert page.
Steel Warehouse can limit carbon contents to improve thermal cutting, formability, and welding performance.
Defined Sizes
ASTM A709 defines sizes by grade and product type. Plates are defined up to 4” in thickness.
Thermal Cutting
Laser and plasma cutting is similar to weldability in terms of the heated cut edge hardening and cracking.
Bendability
ASTM A709 refers to ASTM A6 for bending guarantees.
Available Customizations
Notes from the Technical Group
-
Service temperatures determine the impact testing temperature for tension components:
- Zone 1: minimum service temperature of 0˚F
- Zone 2: minimum service temperature below 0˚F to -30˚F
- Zone 3: minimum service temperature below -30˚F to -60˚F
- ASTM A709 seems to disallow thermos-mechanical control processed (TMCP) steel for Grade HPS 100W. This means Grade HPS 100W will not be furnished with coil product.
