Medium Carbon Steel is a widely used category of carbon steel containing approximately 0.30% to 0.60% carbon and 0.60% to 1.65% manganese. This composition provides a balanced combination of strength, hardness, ductility, toughness, and wear resistance, positioning it between low-carbon (mild) steel and high-carbon steel.
Due to its excellent heat-treatment response and cost effectiveness, medium carbon steel is extensively used in automotive components, engineering parts, industrial machinery, construction elements, and forged products.
Typical Chemical Composition
| Element | Typical Range (%) |
|---|---|
| Carbon (C) | 0.30 – 0.60 |
| Manganese (Mn) | 0.60 – 1.65 |
| Silicon (Si) | ≤ 0.40 |
| Sulphur (S) | ≤ 0.050 |
| Phosphorus (P) | ≤ 0.050 |
| Iron (Fe) | Balance |
Microstructure & Metallurgy
Medium carbon steel typically consists of:
• Ferrite + pearlite in annealed or normalized condition
• Tempered martensite after quenching and tempering
This microstructural adaptability allows mechanical properties to be precisely tailored through controlled heat treatment.
Key Characteristics
Balanced Strength & Ductility
• Higher tensile and yield strength than low-carbon steel
• Retains sufficient ductility for forming, forging, and machining
Heat-Treatable Nature
• Responds well to annealing, normalizing, quenching, and tempering
• Properties optimized for strength, wear resistance, and fatigue life
Improved Wear Resistance
• Higher carbon content increases surface hardness
• Suitable for friction, impact, and cyclic loading conditions
Moderate Weldability
• Weldable with precautions
• Preheating and post-weld heat treatment recommended
Good Machinability
• Best in annealed or normalized condition
• Machinability decreases as hardness increases
Typical Mechanical Properties
| Property | Typical Range |
|---|---|
| Tensile Strength | 550 – 800 MPa |
| Yield Strength | 300 – 600 MPa |
| Hardness (Annealed) | 150 – 250 HB |
| Hardness (Hardened) | Up to 500+ HB |
| Elongation | 10 – 20% |
| Impact Toughness | Moderate (improves after tempering) |
| Density | 7.85 g/cm³ |
| Modulus of Elasticity | ~200 GPa |
Heat Treatment Capabilities
• Annealing – Improves ductility and machinability
• Normalizing – Enhances grain refinement and uniform strength
• Quenching & tempering – Increases hardness, strength, and fatigue resistance
• Surface hardening (flame / induction) – Hard surface with tough core
Available Forms
✔ Hot rolled sheets & plates
✔ Cold rolled sheets & coils
✔ Bars (round, square, flat, hex)
✔ Rods & wire rods
✔ Structural sections (angles, channels, beams)
✔ Forged blocks, billets & rings
✔ Pipes & tubes (seamless & welded)
Manufacturing & Processing
• Produced via BOF or EAF routes
• Continuous casting followed by rolling or forging
• Precision machining and controlled heat treatment for application-specific needs
Applications
Automotive: Crankshafts, connecting rods, axles, gears, transmission shafts
Mechanical & Industrial: Machine parts, couplings, forged components, fasteners
Construction: Load-bearing structures and reinforcement components
Tools & Equipment: Hammers, agricultural tools, springs, wear-resistant parts
Advantages
✔ Excellent strength-to-cost ratio
✔ Good wear and fatigue resistance
✔ Highly heat treatable
✔ Widely available and easy to process
✔ Suitable for forging and machining
Limitations
⚠ Lower weldability than low-carbon steel
⚠ Requires controlled heat treatment to prevent brittleness
⚠ Corrosion protection required in aggressive environments
Comparison: Carbon Steel Types
| Feature | Low Carbon | Medium Carbon | High Carbon |
|---|---|---|---|
| Carbon Content | ≤ 0.25% | 0.30 – 0.60% | ≥ 0.60% |
| Strength | Low | Medium–High | Very High |
| Ductility | High | Moderate | Low |
| Heat Treatable | Limited | Excellent | Excellent |
| Weldability | Excellent | Moderate | Poor |
| Typical Use | Structures | Mechanical parts | Cutting tools |
Why Customers Choose Medium Carbon Steel
Medium carbon steel offers an optimal balance of strength, toughness, wear resistance, and cost efficiency. Its adaptability through heat treatment and availability in multiple industrial forms make it a preferred material for medium-strength engineering and industrial applications across automotive, machinery, construction, and tooling sectors.