Types of Low Carbon Steel: Composition, Grades, and Applications Explained by CSMFG
Learn about the main types of low carbon steel, their composition, properties, and uses. Discover how CSMFG applies different steel grades like AISI 1018 and ASTM A36 in precision manufacturing and global metal fabrication.
Types of Low Carbon Steel: Composition, Grades, and Applications Explained by CSMFG
Low carbon steel — also known as mild steel — is one of the most commonly used materials in the manufacturing industry. With its excellent ductility, weldability, and affordability, it forms the backbone of countless industrial and structural applications. But not all low carbon steels are the same. Understanding the differences between various grades is essential for choosing the right material for your project.
In this article, CSMFG provides an in-depth look at the different types of low carbon steel, their properties, and their typical uses in custom metal fabrication.
What Is Low Carbon Steel?
Low carbon steel typically contains less than 0.25% carbon by weight, making it softer and more ductile than medium or high carbon steels. It is primarily composed of iron (Fe) with small amounts of carbon (C) and manganese (Mn) to improve strength and toughness.
Key characteristics:
- Excellent formability — easy to shape and bend
- High weldability — compatible with MIG, TIG, and arc welding
- Affordable cost — cheaper than alloy or stainless steels
- Moderate strength — suitable for light to medium-duty structures
While it lacks the strength of higher carbon steels, its balance between cost, machinability, and performance makes it ideal for everyday industrial use.
How It Differs from Medium and High Carbon Steels
| Property | Low Carbon Steel | Medium Carbon Steel | High Carbon Steel |
|---|---|---|---|
| Carbon Content | <0.25% | 0.25–0.6% | >0.6% |
| Strength | Low–Medium | Medium–High | Very High |
| Ductility | High | Moderate | Low |
| Weldability | Excellent | Moderate | Poor |
| Common Uses | Structural parts, car bodies | Machinery, axles | Springs, cutting tools |
In short:
Low carbon steel is easier to work with, more cost-effective, and widely used for structural and general-purpose applications — while medium and high carbon steels are reserved for higher-strength requirements.
Main Types of Low Carbon Steel
Low carbon steel can be classified by its chemical composition, grade, or standard specification. The most common grading systems include AISI/SAE, ASTM, and their international equivalents.
1. AISI/SAE Grades
- AISI 1006 / 1008: Extra-low carbon content for superior formability; ideal for deep-drawn components such as automotive panels.
- AISI 1010 / 1015: Balanced strength and ductility; used for fasteners, tubing, and stamped parts.
- AISI 1018 / 1020: General-purpose steels with excellent machinability and weldability; used in shafts, gears, and brackets.
Each grade varies slightly in carbon and manganese levels, affecting hardness and machinability.
2. ASTM Standard Grades
- ASTM A36: One of the most common structural steel grades, offering good weldability and strength for construction beams and plates.
- ASTM A283 / A285: Plate steels used for pressure vessels and forming operations.
3. Global Equivalents
| Standard | Grade | Region |
|---|---|---|
| GB (China) | Q195, Q215, Q235 | Asia |
| JIS (Japan) | SS330, SS400 | Japan |
| DIN/EN (Europe) | S235JR, S275JR | Europe |
| ASTM (US) | A36, A283 | North America |
This global compatibility ensures CSMFG can meet international clients’ diverse material requirements.
Manufacturing Forms and Processing Options
Low carbon steel is available in multiple forms to suit different production methods:
- Sheet / Plate / Coil: Used for automotive panels, machinery covers, and general fabrication.
- Bar / Rod: Common in mechanical components like bolts, shafts, and supports.
- Pipe / Tube: Used in furniture, handrails, and fluid transport systems.
Processing Methods:
- Hot Rolled (HR): Cost-effective, with rougher surfaces, used for structural applications.
- Cold Rolled (CR): Smooth surface finish and tighter tolerances, ideal for decorative or precision parts.
- Annealed: Heat-treated to enhance ductility for forming and bending.
At CSMFG, clients can choose from a wide variety of material forms and finishes based on performance and cost requirements.
Mechanical and Physical Properties
Typical ranges for low carbon steel:
| Property | Value Range |
|---|---|
| Tensile Strength | 250–400 MPa |
| Yield Strength | 200–300 MPa |
| Elongation | 25–40% |
| Hardness | 120–180 HB |
| Density | 7.85 g/cm³ |
These properties make it ideal for forming, machining, and welding operations where moderate strength and high ductility are needed.
Common Applications of Low Carbon Steel
Low carbon steel is used across nearly every manufacturing sector due to its versatility:
- Automotive Industry – Body panels, brackets, chassis parts, and wheel hubs.
- Construction & Infrastructure – Beams, frames, and general structural supports (ASTM A36).
- Machinery & Equipment – Shafts, gears, housings, and enclosures.
- Consumer Goods – Home appliances, furniture, and decorative fixtures.
- Piping & Tubing – Low-pressure fluid transport, HVAC, and industrial conduits.
Example:
CSMFG regularly supplies low carbon steel parts to clients in the automotive and machinery sectors, ensuring tight tolerances, smooth finishes, and consistent material performance.
Surface Treatments and Finishing Options
Since low carbon steel naturally corrodes, surface finishing is essential for durability and appearance. Common treatments include:
- Hot-Dip Galvanizing: Zinc coating for corrosion protection.
- Powder Coating / Painting: Adds color and surface resistance.
- Electroplating: Enhances surface hardness and shine.
- Polishing and Passivation: Improves smoothness and resistance to oxidation.
CSMFG offers multiple finishing options to meet both functional and aesthetic requirements.
Choosing the Right Type of Low Carbon Steel
Selecting the right grade depends on your design, mechanical requirements, and fabrication method.
Quick guide:
- Deep drawing or stamping parts: Choose AISI 1006 / 1008.
- Machined parts or welded frames: AISI 1018 / 1020 or Q235.
- Structural beams and plates: ASTM A36 or S235JR.
CSMFG’s engineering team provides professional consultation to help clients select the most cost-effective and reliable material for their projects.
CSMFG’s Expertise in Low Carbon Steel Fabrication
With decades of experience in custom steel manufacturing, CSMFG delivers precision and consistency across every stage of production.
Capabilities include:
- CNC machining and milling
- Laser cutting and bending
- Welding and forming
- Surface finishing and assembly
- ISO 9001-certified quality control
From prototypes to mass production, CSMFG ensures every component meets the required standards of strength, dimensional accuracy, and finish quality.
Why Choose CSMFG for Low Carbon Steel Projects?
- Access to multiple global standards (ASTM, JIS, DIN, GB)
- Advanced equipment for both hot and cold forming
- Professional material selection and engineering support
- Efficient global shipping and competitive pricing
- Proven reliability with clients across automotive, construction, and energy sectors
For full capabilities, visit https://www.csmfg.com/.
Conclusion
Low carbon steel remains the go-to material for cost-efficient, high-quality metal fabrication. Its adaptability, formability, and availability make it ideal for a wide range of industrial and consumer applications.
By leveraging years of expertise and advanced manufacturing technologies, CSMFG ensures every low carbon steel component is made to precise specifications — on time and within budget.
👉 Contact CSMFG today to discuss your material requirements and discover how our custom metal fabrication services can support your next project.
FAQs
Q1: What’s the difference between AISI 1018 and 1020 steel?
AISI 1020 has slightly higher carbon content, offering more strength but slightly less ductility than 1018.
Q2: Can low carbon steel be heat-treated?
Yes, though traditional hardening is limited. Processes like annealing, carburizing, or normalizing can enhance surface hardness and machinability.
Q3: Does CSMFG provide material certifications?
Yes. All materials can be supplied with Mill Test Reports (MTRs) upon request.
CSMFG — Your Reliable Partner in Low Carbon Steel Fabrication.
For more information, visit https://www.csmfg.com.