What is the Difference Between Carbon Steel and Mild Steel?
Many buyers, engineers, and project managers often ask:
“Is mild steel the same as carbon steel?”
“Which one should I choose for my project?”
Short Answer:
Mild steel is a type of carbon steel with very low carbon content (typically below 0.25%).
All mild steel is carbon steel, but not all carbon steel is mild steel.
What is Carbon Steel?
Definition:
Carbon steel is any steel that primarily contains iron and carbon, with carbon content up to 2.1% by weight.
Types of Carbon Steel:
- Low Carbon Steel (Mild Steel): Up to 0.30% carbon
- Medium Carbon Steel: 0.30% – 0.60% carbon
- High Carbon Steel: 0.60% – 2.1% carbon
Used in: Structural plates, pressure vessels, pipelines, and wear-resistant components.
What is Mild Steel?
Definition:
Mild steel is low carbon steel with carbon content typically between 0.05% to 0.25%.
Features:
- Easy to weld
- Ductile and malleable
- Cost-effective
Common Mild Steel Grades:
- ASTM A36
- IS 2062 Grade B
- JIS SS400
- EN 10025 S275JR
Key Property Comparison – Carbon Steel vs Mild Steel
| Property | Mild Steel | Higher Carbon Steel |
|---|---|---|
| Carbon Content | Up to 0.25% | 0.30% – 2.1% |
| Weldability | Excellent | Moderate to poor (at high carbon) |
| Strength | Lower | Higher |
| Hardness | Lower | Higher |
| Ductility | High | Lower |
Which Standards Cover Mild and Carbon Steel Plates?
| Standard | Type |
|---|---|
| ASTM A36 | Mild Steel |
| IS 2062 | Mild Steel |
| EN 10025 S275JR | Mild Structural Steel |
| ASTM A516 Gr 70 | Medium Carbon Steel |
| EN 10025 S355JR | Medium Carbon Steel |
For pressure vessels, you need medium carbon grades like A516, not mild steel.
Thickness Range Comparison
| Grade | Thickness Range |
|---|---|
| Mild Steel | 6 mm to 150 mm |
| Medium/High Carbon Steel | 6 mm to 120 mm |
Both categories available in cut-to-size and standard dimensions.
Heat Treatment Difference
| Property | Mild Steel | Medium/High Carbon Steel |
|---|---|---|
| Normalized | Optional | Common |
| Quenched & Tempered | Rare | Yes |
| Annealed | Common | Optional |
Weldability & Fabrication Behavior
Mild Steel
- Very easy to weld
- No special pre-heat needed
- May need pre-heating and post-weld heat treatment
- Prone to cracking in thick sections if not welded carefully
Price Difference – Mild vs Medium Carbon Steel
Mild Steel (A36, IS 2062): Most economical
Medium Carbon Steel (A516, S355): 15–30% costlier
High Carbon Steel: Rare in plate form and much more expensive
We offer budget and performance comparison for every inquiry.
Export Markets for Mild and Carbon Steel Plates
Hindustan Steel Corporation exports both categories to:
- UAE
- Saudi Arabia
- South Africa
- Vietnam
- Qatar
- USA
Full container load and part shipment available
Buyer Tip: When to Choose Mild Steel vs Higher Carbon Steel
Choose Mild Steel If:
- You need economical material
- Application is non-critical load
- Easy welding and fabrication are priorities
Choose Medium/High Carbon Steel If:
- Application involves pressure, impact, or high load
- You need higher strength or toughness
Certifications and Test Reports
We provide:
- MTC as per EN 10204 3.1
- Chemical composition report showing carbon percentage
- Third-party inspection (SGS, TUV, Lloyd’s)
- UT and impact test reports for medium carbon grades
Certifications and Test Reports
Supplied with:
- MTC with full chemical composition
- Spectro test report showing actual carbon percentage
- Third-party inspection (SGS, TUV, Lloyd’s)
SEO, AEO, Voice Search Optimized FAQs – Carbon Steel vs Mild Steel
What is the carbon content in mild steel?
Up to 0.25%.
Which is stronger – mild steel or high carbon steel?
High carbon steel.
Which steel is suitable for pressure vessels: mild or medium carbon?
Medium carbon (A516).
What is the difference between IS 2062 and A516?
Structural vs Pressure Vessel grade.
Can mild steel be used for bridges?
For light load bridges, yes
What is the typical thickness range for mild steel plates?
6 mm to 150 mm.
Where can I get carbon content test reports for both?
WhatsApp, Email, or Call us for a fast quote
Contact Hindustan Steel Corporation today
Ask for:
- Carbon content comparison PDF
- Best price for mild vs medium carbon steel plates
- Thickness-wise stock list