Carbon Content in Carbon Steel Plates – Explained for Buyers

How Much Carbon is Present in Carbon Steel Plates?

When buying carbon steel plates, one of the most frequent buyer queries is:
“What is the carbon content?”

The answer depends on the grade and standard you’re choosing.

Low Carbon Steel Plates: Less than 0.30% Carbon
Medium Carbon Steel Plates: 0.30% to 0.60% Carbon
High Carbon Steel Plates: Above 0.60% Carbon

At Hindustan Steel Corporation, we stock and export all three categories.

Why Does Carbon Content Matter in Steel Plates?

Carbon content directly affects:

• Strength
• Toughness
• Hardness
• Weldability

Higher carbon means stronger steel, but also lower ductility and weldability.
Lower carbon means easier welding and better formability.

Carbon Levels in Popular Carbon Steel Plate Grades

Grade	Approx. Carbon Content
ASTM A36	0.25% Max
IS 2062 Grade B	0.22% Max
ASTM A516 Gr 70	0.27% Max
EN 10025 S275	0.25% Max
EN 10025 S355	0.23% Max
JIS G3101 SS400	0.25% Max
ASTM A283 Gr C	0.24% Max

For critical projects, we supply plates with certified chemical analysis.

How Carbon Content Affects Steel Plate Applications

Carbon Level	Typical Applications
Low Carbon (<0.30%)	Structural fabrication, bridges, tanks
Medium Carbon (0.30–0.60%)	Machinery parts, rail components
High Carbon (>0.60%)	Wear parts, knives, tools

Most carbon steel plates used in fabrication and construction fall in the low to medium carbon range.

Carbon Content Limits in Global Standards

Standard	Max Carbon %
ASTM A36	0.25
ASTM A516 Gr 70	0.27
IS 2062 Grade B	0.22
EN 10025 S275	0.25
EN 10025 S355	0.23
JIS G3101 SS400	0.25

Exact limits can vary slightly by plate thickness.

Thickness vs Carbon Content

Heat Treatment Impact on Carbon Content

Carbon doesn’t change during heat treatment, but its effect on plate properties changes.

Process	Effect
Normalizing	Refines grain, improves toughness
Quenching & Tempering	Boosts hardness & strength
Annealing	Improves ductility

Weldability Considerations

• Low carbon steels (like A36, IS 2062) – Excellent weldability
• Higher carbon steels (medium/high) – Need pre-heating and post-weld heat treatment
• Hydrogen cracking risk increases with higher carbon content.

Surface Finish & Testing Services

We offer:

• Carbon content certification
• Spectro analysis report
• Third-party inspection (SGS, TUV, Lloyd’s)
• Shot-blasting & primer-coating for corrosion protection

Technical Standard & Chemical Composition Differences

Parameter	IS 2062 Grade B	ASTM A36
Standard	IS 2062 (Indian)	ASTM A36 (American)
Carbon Content	0.22% max	0.26% max
Manganese	1.50% max	0.60–0.90%
Sulphur & Phosphorus	0.05% max	0.04% max
Silicon	Optional	Optional

Export Support for Carbon Steel Plates with Specified Carbon Content

We export low and medium carbon steel plates to:

• UAE
• Saudi Arabia
• South Africa
• Vietnam
• USA

CIF, FOB, and Ex-Works options available

Heat Treatment Options

Condition	IS 2062	ASTM A36
As-Rolled	✅	✅
Normalized	Available (on request)	Optional (Rare)
Impact Tested Grades	J0/J2 for IS 2062	Optional for A36

Buyer Tip: How to Specify Carbon Content in Your Inquiry

When sending RFQ:

• Mention grade/standard (e.g., A36, IS 2062)
• Specify if max carbon level certification is needed

If required, request low carbon variant for improved weldability

Certifications & Test Reports for Carbon Content

We provide:

• Mill Test Certificates (MTC) with carbon percentage
• Spectrochemical analysis
• Third-party lab test reports
• Impact test and UT reports (on request)

FAQs Carbon Content in Carbon Steel Plates