C-38 carbon steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon steel specifically for C-38, designed for medium strength engineering applications where good toughness, machinability, and reliable mechanical performance are required. C-38 is a medium carbon, unalloyed engineering steel that offers a balanced combination of strength and toughness with better machinability than higher carbon grades such as c-45, C-48, and C-50.

C-38 responds well to normalizing and quenching & tempering, providing improved Mechanical properties while maintaining good ductility. This grade is widely used in general engineering, automotive, and machinery applications where cost-effectiveness and processability are important.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.35 – 0.40	Provides moderate strength and hardness
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 – normalized / quenched & tempered)

• Tensile strength: 520 – 680 MPa
• Yield strength: 300 – 420 MPa
• Hardness: 170 – 220 hb (up to ~30–35 hrc after heat treatment)
• Impact toughness: good
• Wear resistance: moderate

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

Heat treatment

• annealing: used to improve machinability and soften the steel for ease of processing.
• normalizing: refines grain structure and improves strength and toughness balance.
• quenching: heating to approximately 800 – 840°c followed by oil or water quenching to increase hardness.
• tempering: performed to relieve internal stresses and improve toughness while retaining required strength.

Proper heat treatment ensures consistent performance of C-38 in engineering applications.

Key features and benefits

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

Typical applications

• shafts and axles
• gears and pinions for moderate loads
• automotive and machine components
• fasteners and general engineering parts
• forged and machined components

Equivalent steel grades

C-38 has several comparable and equivalent grades, including:

• EN8 / EN8D (bs standard range)
• c35 / c40 (din / en 10083 range)
• aisi 1038 (american standard)
• is 1570 (part 2) – indian standard

Why choose C-38 for your application?

C-38 offers an ideal combination of machinability, toughness, and adequate strength, making it suitable for components that do not require extreme hardness. Its excellent processability and economical cost make it a practical choice for a wide range of general engineering and automotive applications.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
C-38	0.35 – 0.40	Shafts, gears, machine parts	Normalizing / q&t	Good machinability and toughness
C45	0.40 – 0.50	General engineering parts	Q&t	Higher hardness than C-38
C48	0.45 – 0.50	Gears and axles	Q&t	Higher strength
Aisi 1038	0.35 – 0.40	Automotive & machinery parts	Q&t	American equivalent

Summary

C-38 is a medium carbon steel designed for applications requiring good toughness, machinability, and reliable mechanical performance. With consistent quality, good heat treatment response, and cost-effective pricing, C-38 remains a popular choice for general engineering use.