Product Introduction

S20C Carbon Steel Round Bar, adhering to JIS G4051 standards, is a medium-carbon steel with 0.18-0.23% carbon, 0.30-0.60% manganese, 0.15-0.35% silicon, and trace phosphorus/sulfur. It exhibits a yield strength of ≥245 MPa, tensile strength ≥400 MPa, and elongation ≥25-28%, balancing strength, ductility, and toughness. This material excels in machinability, weldability, and formability, allowing seamless processing via cutting, bending, forging, and welding. Common applications include manufacturing shafts, gears, bolts, pins, automotive components, and structural frameworks in construction and heavy machinery. Its cost-effectiveness makes it ideal for projects where high-strength alloys are unnecessary. With consistent mechanical properties, broad industry compatibility, and reliable performance, S20C remains a staple in industrial engineering, offering an optimal blend of strength, versatility, and affordability.

About Us

Zhongxi Metal is a professional manufacturer engaged in the research, development, production, sale and service.,  is committed to providing one-stop steel procurement services for global client.

Why Choose S20C Carbon Steel Round Bar?

1. Balanced Mechanical Properties for Versatile Applications

With 0.18–0.23% carbon and controlled manganese/silicon content, S20C achieves a yield strength of ≥245 MPa, tensile strength ≥400 MPa, and 25–28% elongation. This balance ensures optimal strength, ductility, and toughness for components like shafts, gears, and bolts in automotive, machinery, and construction sectors.

2. Enhanced Machinability & Formability

Low carbon content and fine grain structure enable excellent machinability (cutting, drilling) and formability (cold/hot bending, forging). Annealing or normalizing further improves surface finish and dimensional accuracy, reducing tool wear and production costs.

3. Cost-Effective Medium-Carbon Solution

S20C provides a cost-efficient alternative to high-alloy steels for medium-strength applications. Its affordability makes it ideal for mass-produced components (e.g., fasteners, pins) where extreme hardness is unnecessary but reliability is critical.

4. Heat Treatment Adaptability

Through quenching and tempering, S20C achieves enhanced hardness (up to 50 HRC) and wear resistance for high-load parts like gears and crankshafts. Case hardening (carburizing/nitriding) extends surface durability without compromising core toughness.

5. Corrosion Mitigation via Surface Treatments

While susceptible to corrosion, S20C’s lifespan is extendable through protective coatings (galvanization, epoxy paints) or surface treatments. This adaptability ensures reliable performance in humid/marine environments when paired with anti-corrosion strategies.

We have our own Physical & Chemical Testing Center Lab to guarantee our product quality. Our test items & instrument fully meet international standards.

Applications of Carbon Steel Round Bar

As a basic industrial material, carbon steel round bars play a key role in many fields with their excellent mechanical properties and wide applicability. In the field of construction and infrastructure, carbon steel round bars are often used to manufacture core components such as beams, columns, bridges, and steel structures. Their high strength and good plasticity can withstand complex mechanical loads and ensure structural stability. For example, low-carbon steel round bars (carbon content ≤ 0.25%) are widely used in steel bars, bolts, and mechanical parts due to their easy processing and good welding performance; medium-carbon steel round bars (carbon content 0.25%~0.6%) are suitable for high-load components such as shafts, gears, and seamless steel pipe billets due to their balance of strength and toughness. In addition, in the energy industry, carbon steel round bars are used for oil/gas pipelines, power generation equipment, and nuclear power plant structural parts. Their high temperature resistance and corrosion resistance meet the requirements of extreme working conditions.

In the field of automobile and machinery manufacturing, the application of carbon steel round bars is also indispensable. In the automotive industry, it is used in components such as body frames, chassis, engine brackets, and wheels to provide safe and reliable mechanical support. High carbon steel round bars (carbon content > 0.6%) are often used to manufacture cutting tools, bearings and springs due to their extremely high hardness to ensure wear resistance and service life. For example, W1 tool steel round bars are used to make chisels, punches, woodworking tools, swords and knives with their excellent wear resistance, hardenability and toughness. They are especially suitable for cutting tasks that require high precision and durability. In addition, carbon steel round bars are also widely used in the manufacture of equipment such as pipes, boilers, containers, railway vehicles and electric welders. Special purpose round steel (such as prestressed steel wire, spring round steel) shows unique value in specific fields. Its diverse performance and specifications make carbon steel round bars an indispensable basic material in modern industry.

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As a leading company, Zhongxi Metal is known for our excellent product quality and professional services, providing our customers with a reliable partner. We have a global sales network that can meet the needs of customers in different countries and regions.If you need more information about us or have any other needs, please feel free to contact us. We look forward to working with you to create a better future.