C-45 carbon steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon steel specifically for C 45, designed for higher strength engineering applications where excellent hardness, wear resistance, and toughness are required. C 45 is a medium-high carbon, unalloyed engineering steel that offers a superior combination of strength, hardness, and wear resistance compared to lower carbon grades such as C 30 , C 35, and C 40.

Due to its higher carbon content, C 45 shows excellent response to quenching and tempering and is widely used in automotive, machine tool, and general engineering applications subjected to high mechanical loads. C 45 provides consistent mechanical properties, good machinability in annealed condition, and cost-effective performance for a broad range of industrial components.

Chemical composition

Element Content (%) Function / effect
Carbon (c) 0.40 – 0.50 Provides high strength, hardness, and wear resistance
Manganese (mn) 0.60 – 0.90 Improves hardenability, strength, and toughness
Sulphur (s) Max 0.050 Improves machinability; controlled to prevent brittleness
Phosphorus (p) Max 0.050 Aids machinability; limited to maintain toughness
Silicon (si) 0.05 – 0.35 Acts as a deoxidizer and increases strength
Chromium (cr) Nil Not intentionally added
Nickel (ni) Nil Not present
Molybdenum (mo) Nil Not present
Other elements No significant alloying additions

Mechanical properties (typical – quenched & tempered)

  • Tensile strength: 600 – 800 MPa
  • Yield strength: 350 – 500 MPa
  • Hardness: 200 – 280 hb (up to ~30–35 hrc after heat treatment)
  • Impact toughness: moderate to good
  • Wear resistance: good to very good

( Mechanical properties may vary depending on section size, heat treatment, and service conditions)

Heat treatment

  • annealing: used to soften the steel and improve machinability before final machining.
  • normalizing: refines grain structure and improves uniformity of mechanical properties.
  • quenching: heating to approximately 820 – 860°c followed by oil or water quenching to achieve high hardness.
  • tempering: reheating to a controlled temperature to reduce brittleness and improve toughness while maintaining required strength.

The heat treatment process can be customized to achieve the desired balance of hardness, strength, and toughness for specific applications.

Key features and benefits

  • higher strength and hardness compared to lower carbon steels
  • excellent response to quenching and tempering
  • good wear resistance for high-load applications
  • good machinability in annealed condition
  • suitable for forging and general engineering use
  • cost-effective and widely available material

Typical applications

  • shafts, axles, and spindles
  • gears, pinions, and couplings
  • crankshafts and camshafts
  • automotive and machine tool components
  • bolts, studs, and high-strength fasteners
  • forged and machined engineering parts

Equivalent steel grades

C 45 has several international equivalents and comparable grades, including:

  • en8 (bs en standard)
  • c45 / 1.0503 (din / en 10083)
  • aisi 1045 (american standard)
  • is 1570 (part 2) – indian standard

Why choose C 45 for your application?

C 45 offers an excellent combination of high strength, hardness, and wear resistance, making it ideal for components subjected to high mechanical loads. Its reliable heat treatment response, good machinability, and economical cost make it a practical and versatile choice for a wide range of engineering and automotive applications.

Comparison table for similar grades

Grade Carbon (%) Key applications Heat treatment Comments
C 45 0.40 – 0.50 Shafts, gears, axles Quenching & tempering High strength and wear resistance
En8 0.35 – 0.45 General engineering parts Normalizing / q&t Common equivalent
C40 0.37 – 0.44 Machine components Normalizing Lower strength than C 45
Aisi 1045 0.43 – 0.50 Automotive & machinery parts Quenching & tempering American equivalent

Summary

C 45 is a high-performance medium-high carbon steel designed for demanding engineering applications. With its excellent strength, wear resistance, and heat treatment capability, C 45 delivers consistent performance, long service life, and excellent value for heavy-duty components.