Overview
ASTM A36/A36M covers carbon structural steel, while ASTM A572/A572M covers high-strength low-alloy columbium-vanadium structural steel in named grades and product limits. They are product specifications, not universal strength labels, and must be ordered with the applicable A6 general requirements, member geometry, toughness and fabrication controls.
Designation and acceptance
ASTM A36/A36M-19 and ASTM A572/A572M-25 serve overlapping structural markets but define different material families. A36 is commonly selected for general carbon-steel shapes, plates and bars; A572 provides grade-based HSLA options. Neither designation by itself defines the finished member, connection design, weld procedure, coating, inspection class or project acceptance. ASTM A6/A6M-26a supplies common rolled-structural-product requirements.
Members and selection
| Designation | Selection context |
|---|---|
| ASTM A36 | General carbon structural steel where the drawing, design code and thickness/product limits specifically permit A36. |
| ASTM A572 Grade 42 | A lower-strength A572 family option that still requires the exact product and thickness scope to be checked. |
| ASTM A572 Grade 50 | Widely specified HSLA structural grade; do not treat the 50 ksi yield label as the entire purchase specification. |
| ASTM A6/A6M | General requirements governing dimensions, tolerances, testing, reports and ordering interaction for rolled structural products. |
Comparison framework
| Criterion | Decision context |
|---|---|
| Material family | A36 is carbon structural steel; A572 is HSLA columbium-vanadium structural steel with explicit strength grades. |
| Product and thickness | Availability and mechanical requirements depend on shape, plate or bar form and the thickness limits stated by the selected specification. |
| Toughness | Notch toughness is not established by a casual grade substitution; invoke the required test temperature, energy and supplementary requirement. |
| Substitution | Higher nominal yield strength does not automatically preserve ductility, weld procedure, connection behavior, availability or design-code compliance. |
Performance
- Design strength must use the governing specification, thickness and structural code rather than a supplier's generic grade label.
- Weldability depends on chemistry, product thickness, restraint, hydrogen control and the qualified welding procedure.
- Fracture-critical, seismic, fatigue or low-temperature service can require toughness and traceability beyond basic tensile acceptance.
Orderable product scope
- Hot-rolled structural shapes and sections within the selected specification scope.
- Structural plate ordered with exact thickness, width, length, flatness and edge condition.
- Structural bars and selected miscellaneous products only where the applicable standard expressly includes them.
Processing
- Confirm mill route, rolling condition and any heat-treatment requirement before design release.
- Qualify cutting, forming and welding procedures for the grade, thickness and restraint.
- Preserve heat and piece traceability through fabrication, blasting, coating and erection marking.
Applications
- Building frames, platforms and industrial support structures designed to the applicable code.
- Bracing, gussets, base plates and fabricated structural assemblies after connection review.
- Infrastructure components where drawings explicitly select the standard, grade and toughness class.
Selection
- Start with the structural design documents and product form, then select A36 or a named A572 grade.
- Review thickness-dependent strength, toughness, welding and availability before approving alternatives.
- Keep coating and fire-protection systems as separate, fully specified procurement layers.
Procurement
- State ASTM A36/A36M-19 or ASTM A572/A572M-25 and the exact grade, without mixing A and A/M units.
- List shape or plate designation, dimensions, quantity, tolerances, edge/end preparation and rolling condition.
- Define impact testing, through-thickness properties, supplementary requirements, weldability data and inspection documents.
- Require ASTM A6/A6M controls, traceability, marking, surface condition, coating preparation and delivery sequence.
Sources and review
ASTM International · 2019, active
ASTM International · 2025, active
ASTM International · 2026a, active