ASTM A36 vs A572 Grade 50: Strength, Uses and Substitution
ASTM A36 vs A572 Grade 50 compared: yield and tensile strength, chemistry, weldability, availability, cost and when each is specified for plates and sections.
Saudi Steel Work Editorial Team · · 3 min read
Short answer: ASTM A36 has a minimum yield of 36 ksi (250 MPa); A572 Grade 50 has 50 ksi (345 MPa), about 38% higher. A572 Gr.50 is preferred where strength-to-weight matters; A36 is common for plates, base plates and general fabrication. A572 Gr.50 can usually replace A36 with engineer approval, but not the other way round.
A36 and A572 Grade 50 are two of the most common American structural steel grades, frequently specified on Saudi projects designed to US codes and in oil and gas facilities.
Properties compared
| Property | ASTM A36 | ASTM A572 Gr.50 |
|---|---|---|
| Min. yield | 36 ksi (250 MPa) | 50 ksi (345 MPa) |
| Tensile | 58–80 ksi (400–550 MPa) | 65 ksi (450 MPa) min. |
| Alloying | Carbon-manganese | High-strength low-alloy (Nb, V) |
| Common products | Plates, bars, angles, channels | Plates, sections |
Where each is used
A36
- Base plates, gussets and connection plates
- Angles and channels for secondary framing
- General fabrication, brackets and supports
A572 Gr.50
- Primary beams and columns
- Heavy plate girders
- Members where weight reduction matters
For American W-shapes, ASTM A992 has largely replaced A572 Gr.50 as the default.
Substitution rules of thumb
- A572 Gr.50 for A36: usually acceptable structurally, but check weldability procedures and get approval.
- A36 for A572 Gr.50: not acceptable without redesign.
- Dual-certified plate (A36/A572-50) is common and simplifies stock.
EN equivalents
A36 sits close to S275 and A572 Gr.50 close to S355, but tolerances, testing and chemistry differ. If your project mixes US and EN standards, confirm equivalence with the engineer. See S275 vs S355.
What to check on certificates
- Correct standard and grade stated
- Yield and tensile results above minimums
- Chemistry within limits
- Heat number matching the material
See mill test certificates explained.
Need plate or sections in A36 or A572? See our steel plates range or request a quote.