SA36 is a general-purpose carbon structural steel used for riveted, bolted, and welded construction of buildings, bridges, and general structures. The SA prefix indicates that the material is accepted under the ASME Boiler and Pressure Vessel Code, which makes it eligible for non-pressure parts in ASME-coded equipment. For practical purposes, SA36 and ASTM A36 are the same material, and the grade is a low-carbon mild structural steel with a minimum yield strength of 36 ksi (250 MPa).
What Is SA36 Steel?
SA36 is the ASME designation corresponding to ASTM A36/A36M, the standard specification for carbon structural steel. It is supplied as hot-rolled plates, bars, and structural shapes including beams, channels, and angles. The base specification is a strength-only grade: it does not mandate Charpy impact testing, so the material is selected where adequate strength, weldability, and economy matter more than guaranteed fracture toughness.
Key Mechanical Properties
Minimum yield strength: 36 ksi (250 MPa) for thicknesses up to 8 in (200 mm).
Tensile strength: 58-80 ksi (400-550 MPa).
Elongation: minimum 20% in 8 in (200 mm) for plates, with the requirements for other product forms given in the standard.
Impact testing: not mandatory in the base specification.
Chemistry: low-carbon steel; the maximum carbon limit varies with product form and thickness (for example 0.26% for structural shapes), with controlled manganese, phosphorus, and sulfur, and optional copper where atmospheric corrosion resistance is requested.
Because of the low carbon content, SA36 is readily weldable by common processes such as SMAW, GMAW, FCAW, and SAW, and it forms and machines predictably.
Where SA36 Steel Is Commonly Used
The main applications fall into five groups:
Building and industrial structures: columns, beams, joists, roof trusses, base plates, and floor framing for warehouses, workshops, and low- to mid-rise buildings.
Machinery and material handling: frames, supports, platforms, walkways, stairs, railings, brackets, and gusset plates.
Transportation equipment: truck frames, trailer beds, and agricultural equipment components.
Non-primary bridge components: access walkways, handrails, and support brackets, while main load-carrying bridge members normally use higher-strength or weathering grades.
ASME-coded pressure equipment: support skirts, legs, base rings, ladders, platforms, and other attachments that do not form the pressure boundary, when the material is ordered to the SA36 designation.
Where SA36 Steel Is Not the Right Choice
SA36 is not intended for pressure-retaining shells, where pressure vessel grades such as SA516 are required. It is also not the best choice for weight-critical designs that need higher yield strength (where HSLA grades such as A572 Grade 50 are used), for low-temperature service that demands guaranteed toughness (where impact-tested grades are specified), or for unprotected corrosive exposure (where weathering steel or coated systems are used). In each case the designer should select a grade with the required guaranteed properties.
SA36 and European Grades
SA36 is sometimes compared with S235JR to EN 10025-2. The two grades are similar in application, but the nominal yield strengths differ: 250 MPa for A36 versus 235 MPa for S235JR for thin sections. Equivalence should therefore be confirmed on a project basis rather than assumed, and the same care applies when S275JR is considered as a higher-strength substitute. A complete comparison must also account for the fact that A36 carries no mandatory impact requirement, while EN grades guarantee Charpy values indicated by their suffix.
Frequently Asked Questions
What is the difference between SA36 and A36? There is no technical difference in mechanical or chemical requirements. A36 is the ASTM structural steel specification, while SA36 is the same material listed in the ASME Boiler and Pressure Vessel Code for use in coded equipment.
What is the yield strength of SA36 steel? The minimum yield strength is 36 ksi (250 MPa) for plates and bars up to 8 in (200 mm) thick.
Can SA36 steel be welded? Yes. SA36 has excellent weldability with common processes (SMAW, GMAW, FCAW, SAW), and preheat is generally not required for light sections.
Can SA36 steel be hot-dip galvanized? Yes. Its simple carbon-silicon composition reacts predictably with molten zinc, making it a suitable candidate for hot-dip galvanizing per the applicable coating standard.
What is SA36 steel equivalent to? It is often compared with S235JR to EN 10025-2. The grades are similar in application, but yield strength differs (250 MPa versus 235 MPa), so equivalence must be verified against the design requirements.
Does SA36 require impact testing? No. Impact testing is not mandatory in the base A36/A36M or SA36 specification; where fracture toughness is required, an impact-tested grade should be specified.