High Carbon Steel is a class of plain carbon steel containing approximately 0.60% to 1.00% carbon. This higher carbon content allows the steel to achieve very high hardness, strength, and wear resistance after heat treatment.
Compared to low and medium carbon steels, high carbon steel offers superior hardness and edge retention, but with reduced ductility and weldability. It is widely used for cutting tools, springs, dies, blades, and wear-intensive components.
Typical Chemical Composition
| Element | Typical Range (%) |
|---|---|
| Carbon (C) | 0.60 – 1.00 |
| Manganese (Mn) | 0.30 – 1.00 |
| Silicon (Si) | ≤ 0.40 |
| Sulphur (S) | ≤ 0.050 |
| Phosphorus (P) | ≤ 0.050 |
| Iron (Fe) | Balance |
Metallurgical Structure & Behavior
• Annealed: Pearlite + ferrite (soft, machinable)
• Hardened: Martensite (very hard, brittle)
• Tempered: Tempered martensite (balanced hardness & toughness)
High carbon content promotes martensitic transformation, fine carbide formation, and strong edge stability under repeated mechanical stress.
Key Characteristics
High Hardness & Strength
• Achieves HRC 55–65 after hardening
• Suitable for high-load and wear-intensive parts
Superior Wear & Abrasion Resistance
• Excellent resistance to surface deformation
• Ideal for dies, blades, springs, and tools
Excellent Edge Retention
• Maintains sharp edges under continuous use
• Widely used in knives, saws, and cutting machinery
Lower Ductility & Toughness
• Increased brittleness compared to low/medium carbon steels
• Proper tempering required to avoid cracking
Heat Treatment & Refining Properties
Annealing: Softens steel, improves machinability
Normalizing: Grain refinement and uniform strength
Quenching: Produces martensitic structure for maximum hardness
Tempering: Reduces brittleness and improves toughness
Surface Hardening: Induction hardening or carburizing for wear surfaces
Typical Mechanical Properties
| Property | Typical Range |
|---|---|
| Carbon Content | 0.60 – 1.00% |
| Tensile Strength | 700 – 1,200 MPa |
| Yield Strength | 400 – 900 MPa |
| Hardness | 45 – 65 HRC (heat treated) |
| Elongation | 5 – 15% |
| Impact Toughness | Low to moderate |
| Density | ~7.85 g/cm³ |
Common High Carbon Steel Grades
AISI / SAE Grades
• AISI 1060: ~0.60% C – springs, knives, wear plates
• AISI 1070: ~0.70% C – agricultural tools, cutting edges
• AISI 1080 / 1085: 0.80–0.85% C – blades, industrial knives
• AISI 1095: ~0.95% C – precision cutting tools, springs
European & British Grades
| Grade | Equivalent |
|---|---|
| EN42 | AISI 1095 |
| C70 / C80 | AISI 1070 / 1080 |
| EN43 | High-carbon spring steel |
Indian Standards (IS)
| IS Grade | Typical Use |
|---|---|
| IS 1570 Gr 3 | Springs, tools |
| IS 2062 (High-C) | Wear parts |
| IS 1079 | High-carbon sheets & strips |
Available Forms
✔ Sheets & plates
✔ Coils & strips
✔ Bars (round, square, flat, hex)
✔ Wire rods & wires
✔ Forged billets & blocks
✔ Precision-ground components
Applications
Tools: Knives, blades, chisels, punches, dies
Springs: Leaf springs, coil springs, high-tension wires
Machinery: Wear plates, gears, bearing components
Construction & Agriculture: Prestressed wires, machine blades
Advantages
✔ Extremely high hardness
✔ Excellent wear resistance
✔ Superior edge retention
✔ Cost-effective versus alloy steels
Limitations
⚠ Low weldability
⚠ Brittle if not properly tempered
⚠ Reduced machinability after hardening
Why Choose High Carbon Steel Grades
High carbon steel grades are selected when maximum hardness, wear resistance, and edge stability are required at competitive cost. Their precise heat-treat response makes them indispensable for tools, springs, cutting equipment, and heavy-duty industrial components.