C-48 carbon steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon steel specifically for C-48, designed for medium to high strength engineering applications where good hardness, toughness, and machinability are required. C-48 is a medium carbon, unalloyed engineering steel that offers a well-balanced combination of strength and toughness with better machinability than higher carbon grades such as C-50, C-55, and C-65.

C-48 responds well to quenching and tempering, providing improved hardness and wear resistance while maintaining good toughness. This grade is widely used in general engineering, automotive, and machinery applications where reliable performance and cost-effectiveness are essential.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.45 – 0.50	Provides good strength, hardness, and wear resistance
Manganese (mn)	0.60 – 0.90	Improves hardenability and toughness
Silicon (si)	0.15 – 0.35	Increases strength and acts as deoxidizer
Phosphorus (p)	Max 0.050	Impurity; limited to maintain toughness
Sulphur (s)	Max 0.050	Improves machinability when controlled
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: 580 – 760 MPa
• Yield strength: 340 – 520 MPa
• Hardness: 210 – 260 hb (up to ~38–42 hrc after hardening)
• Impact toughness: good
• Wear resistance: moderate

( 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 required hardness.
• tempering: performed to reduce brittleness and adjust the required balance between strength and toughness.

Proper heat treatment ensures optimum performance of C-48 in engineering applications.

Key features and benefits

• good balance of strength and toughness
• good machinability compared to higher carbon grades
• reliable response to heat treatment
• suitable for forging and machining
• cost-effective and widely used material
• consistent and stable mechanical properties

Typical applications

• shafts and axles
• gears and pinions
• automotive and machine components
• fasteners and general engineering parts
• forged and heat-treated components

Equivalent steel grades

C-48 has several comparable and equivalent grades, including:

• EN8 (bs standard)
• c45 / c48 (din / en 10083 range)
• aisi 1048 (american standard)
• is 1570 (part 2) – indian standard

Why choose C-48 for your application?

C-48 offers a practical combination of strength, toughness, and machinability, making it ideal for components that require reliable mechanical performance without the excessive brittleness of higher carbon steels. Its good heat treatment response and economical cost make it a versatile choice for a wide range of engineering applications.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
C-48	0.45 – 0.50	Shafts, gears, machine parts	Quenching & tempering	Good machinability and toughness
C45	0.40 – 0.50	General engineering parts	Q&t	Slightly lower hardness
C50	0.47 – 0.55	Gears and axles	Q&t	Higher hardness than C-48
Aisi 1048	0.46 – 0.50	Automotive & machinery parts	Q&t	American equivalent

Summary

C-48 is a medium carbon steel designed for applications requiring good strength and toughness with moderate hardness and wear resistance. With consistent performance, good machinability, and cost-effective pricing, C-48 is a reliable material for general engineering and automotive uses.