C35 carbon steel

Introduction

We manufacture forging ingots, billets, and blooms in carbon steel specifically for C35, designed for medium-to-high strength engineering applications where good hardness, toughness, and machinability are required.

C35 is a medium carbon, unalloyed engineering steel that offers higher strength and hardness than lower carbon grades such as C30 . With its balanced carbon and manganese content, C35 is suitable for components subjected to moderate to heavy mechanical loads. It is widely used in automotive, machinery, and general engineering applications.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.30 - 0.40	Provides increased strength and hardness
Manganese (Mn)	0.60 - 0.90	Improves hardenability, strength, and toughness
Sulfur (s)	0.050 max	Improves machinability; controlled to avoid brittleness
Phosphorus (p)	0.050 max	Aids machinability; limited to maintain toughness
Silicon (si)	0.05 - 0.35	Acts as deoxidizer and enhances 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

(Properties may vary depending on section size and heat treatment conditions)

• tensile strength: approx. 520 - 680 MPa
• yield strength: approx. 300 - 420 MPa
• elongation: approx. 16 - 20%
• hardness (normalized): approx. 160 - 210 hb
• impact toughness: good
• fatigue resistance: moderate to good

Heat treatment

• annealing: improves machinability and relieves internal stresses
• normalizing: refines grain structure and improves strength and toughness
• quenching: increases hardness and tensile strength
• tempering: balances hardness with toughness and reduces brittleness
• C35 is suitable for through hardening for medium load applications

Key features and benefits

• higher strength than low carbon steels
• good hardness and wear resistance
• good machinability in annealed condition
• uniform mechanical properties
• cost-effective medium carbon steel
• suitable for forging, machining, and fabrication

Typical applications

• shafts and axles
• gears and pinions (moderate load)
• bolts, studs, and fasteners
• forged engineering components
• automotive and agricultural parts

Equivalent steel grades

• C35 (is)
• EN8 / EN8D (approximate)
• AISI 1035
• DIN C35 (1.0501)
• JIS s35c

Why choose C35 for your application?

C35 is the ideal choice when higher strength and hardness than C30  are required without the need for alloying elements. Its excellent response to heat treatment, good machinability, and cost-effectiveness make it a preferred material for general engineering and automotive components.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
C35	0.30 - 0.40	Shafts, gears, forgings	Normalizing / q&t	Good strength and toughness
C30	0.25 - 0.35	Fasteners, shafts	Normalizing	Lower strength than C35
EN8	0.35 - 0.45	Engineering parts	Normalizing / q&t	Higher hardness
AISI 1035	0.32 - 0.38	Automotive components	Normalizing / q&t	American equivalent
S35C	0.33 - 0.38	Machined parts	Normalizing	Japanese equivalent

Summary

C35 is a medium carbon engineering steel offering a strong combination of strength, toughness, and machinability. It is widely used in machined and forged components subjected to moderate to heavy mechanical loads.