ASTM A572 Grade 50 vs C55E: 47% composition overlap. Significantly different materials serving different application areas.
ASTM A572 Grade 50 vs C55E
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.
C55E
1.1203
High-carbon unalloyed Q&T steel — 0.52-0.60% C. Modern designation for Ck55. Good strength after Q&T (UTS 800-950 MPa) and excellent surface hardness after induction hardening (HRC 56-60). Used for rail wheels, crankshafts, heavy-duty shafts, and wear parts.
| ASTM A572 Grade 50 | C55E | |
|---|---|---|
| Material Number | — | 1.1203 |
| Category | Carbon Steel | Carbon Steel |
| Standard | ASTM A572 | EN 10083-2 |
Chemical composition (wt%)
| Element | ASTM A572 Grade 50 | C55E | Overlap |
|---|---|---|---|
| C | 0–0.23% | 0.52–0.6% | No overlap |
| Si | 0–0.4% | 0–0.4% | OK |
| Mn | 0–1.35% | 0.6–0.9% | OK |
| P | 0–0.04% | 0–0.025% | OK |
Mechanical properties
| Property | ASTM A572 Grade 50 | C55E | Unit |
|---|---|---|---|
| tensile_strength | ≥ 450 | 800–950 | MPa |
| yield_strength | ≥ 345 | 500–600 | MPa |
| elongation | ≥ 18 | 12–16 | % |
Compatibility Assessment
ASTM A572 Grade 50 and C55E have significantly different compositions (47% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is ASTM A572 Grade 50 the same as C55E?
ASTM A572 Grade 50 and C55E have a 47% composition overlap. They are generally not directly interchangeable.
Can I replace ASTM A572 Grade 50 with C55E?
Generally not recommended. The compositions differ significantly (47% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between ASTM A572 Grade 50 and C55E?
The main differences are in the following elements: C. ASTM A572 Grade 50 is a Carbon Steel grade, while C55E is a Carbon Steel grade.
Related Comparisons
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Data provided for reference only. Always verify against the applicable specification for critical applications.
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