ASTM A572 Grade 50 vs ASTM A36: Both US structural steels — A572-50 has ~40% higher yield
ASTM A572 Grade 50 vs ASTM A36
Side-by-side chemical composition and mechanical property comparison.
Overview
ASTM A572 Grade 50
The most widely used structural steel grade in the United States. 345 MPa (50 ksi) yield strength HSLA steel. Has largely replaced A36 for structural applications due to higher strength-to-weight ratio. Used for building frames, bridges, heavy equipment, and general structural fabrication.
ASTM A36
K02600
The most common structural carbon steel in the US. Low carbon content with good weldability and machinability. Used for buildings, bridges, construction equipment, and general structural purposes. Minimum yield strength 36 ksi (250 MPa).
| ASTM A572 Grade 50 | ASTM A36 | |
|---|---|---|
| Material Number | — | K02600 |
| Category | Carbon Steel | Carbon Steel |
| Standard | ASTM A572 | ASTM A36/A36M |
Chemical composition (wt%)
| Element | ASTM A572 Grade 50 | ASTM A36 | Overlap |
|---|---|---|---|
| C | 0–0.23% | 0–0.26% | OK |
| Si | 0–0.4% | 0–0.4% | OK |
| Mn | 0–1.35% | 0–1.03% | OK |
| P | 0–0.04% | 0–0.04% | OK |
Mechanical properties
| Property | ASTM A572 Grade 50 | ASTM A36 | Unit |
|---|---|---|---|
| tensile_strength | ≥ 450 | 400–550 | MPa |
| yield_strength | ≥ 345 | ≥ 250 | MPa |
| elongation | ≥ 18 | ≥ 20 | % |
Compatibility Assessment
A572 Gr 50 has 345 MPa yield (vs 250 MPa for A36), allowing lighter structural designs. Both readily weldable. A572-50 has largely replaced A36 as the standard US structural steel.
Frequently Asked Questions
Is ASTM A572 Grade 50 the same as ASTM A36?
ASTM A572 Grade 50 and ASTM A36 have a 70% composition overlap. Both US structural steels — A572-50 has ~40% higher yield
Can I replace ASTM A572 Grade 50 with ASTM A36?
In many cases, yes. The compositions overlap significantly (70%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between ASTM A572 Grade 50 and ASTM A36?
The main differences are in the following elements: overall alloying content. ASTM A572 Grade 50 is a Carbon Steel grade, while ASTM A36 is a Carbon Steel grade.
Related Comparisons
View full data for each material:
Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.