30C8 carbon steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon steel specifically for 30C8, designed for medium strength engineering applications where a balance of strength, toughness, and machinability is required.

30C8 is a medium carbon, unalloyed engineering steel that offers better strength and hardness than low carbon grades such as 15C8 and C-20, while maintaining good toughness and machinability in the annealed or normalized condition.

This grade responds well to heat treatment and is widely used for general engineering and automotive components subjected to moderate mechanical loads.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.25 – 0.35	Provides strength, hardness, and wear resistance
Manganese (mn)	0.60 – 0.90	Improves hardenability and toughness
Sulphur (s)	0.050 max	Improves machinability when controlled
Phosphorus (p)	0.050 max	Controlled to maintain toughness
Silicon (si)	0.10 – 0.35	Increases strength and elasticity
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: 500 – 650 MPa
• Yield strength: 300 – 400 MPa
• Elongation: 18 – 22 %
• Hardness: 150 – 200 HB

(properties may vary depending on heat treatment and section size)

Heat treatment

• Annealing: improves machinability and softness
• Normalizing: refines grain structure and improves mechanical properties
• Quenching: heating to 820 – 860°c followed by rapid cooling
• Tempering: improves toughness and reduces brittleness
• Case hardening: possible for selective wear applications

Key features and benefits

• Good balance of strength and toughness
• Better wear resistance than low carbon steels
• Good machinability in annealed condition
• Cost-effective and easily available
• Suitable for forging and machining

Typical applications

• Shafts and axles
• Gears and pinions (light to medium duty)
• Spindles and pins
• Bolts, studs, and fasteners
• Automotive and general engineering parts

Equivalent Steel Grades

• 30C8 (Is Standard)
• En C30 / 1.0528 (En Standard – Closest Equivalent)
• Din 1.0528
• Aisi 1030

Why Choose 30C8 For Your Application?

30C8 Is An Ideal Material For Applications Requiring Moderate Strength And Good Machinability. Its Ability To Be Heat Treated Allows Flexibility In Achieving Desired Mechanical Properties, Making It Suitable For A Wide Range Of Engineering Components.

Comparison table for similar grades

Grade	Carbon (%)	Strength level	Typical applications
15C8	0.12 – 0.18	Low	Case hardened parts
C-20	0.17 – 0.23	Low–medium	Fabricated components
30C8	0.25 – 0.35	Medium	Shafts, axles
40C8	0.35 – 0.45	Medium–high	Gears, fasteners
45 c8	0.40 – 0.50	High	Automotive parts

Summary

30C8 carbon steel is a versatile medium carbon grade offering a practical combination of strength, toughness, and machinability. It is ideal for general engineering and automotive applications where moderate load-bearing capability and cost-effective performance are required.