Carbon Steel Technical Catalogue
Comprehensive technical specifications and application guide for low and medium carbon steel bars
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Low Carbon Steels
Easily formable, welding-friendly low carbon steel bars. Ideal for general construction, structural elements, and welded fabrication applications.
Product Dimension Table
| Form | Diameter/AF (mm) | Tolerance | Standard Length (m) | Surface Finish |
|---|---|---|---|---|
| Round | 4 - 20 | h9 | 3 (max 6) | Ra 0.8 - 1.6 |
| Round | 20 - 50 | h9 / h10 | 3 (max 6) | Ra 0.8 - 1.6 |
| Round | 50 - 100 | h10 / h11 | 3 (max 6) | Ra 1.6 - 3.2 |
| Hexagon | 6 - 30 | h9 | 3 (max 6) | Ra 0.8 - 1.6 |
| Hexagon | 30 - 60 | h10 / h11 | 3 (max 6) | Ra 1.6 - 3.2 |
| Square | 6 - 30 | h9 | 3 (max 6) | Ra 0.8 - 1.6 |
| Square | 30 - 60 | h10 / h11 | 3 (max 6) | Ra 1.6 - 3.2 |
Key Features
- Excellent weldability
- Easy forming and bending capability
- Precision surface finish via cold drawing
- Available in 3 forms (round, hex, square)
- Consistent mechanical properties
- Economical and readily available
- Can be used without heat treatment
- High toughness values
Applications
- Structural elements and construction
- Bridge fixtures and connectors
- Pipelines and fittings
- General manufacturing and fabrication
- Welded structures
- Bolt and nut production (low strength class)
- Automotive body parts
- Furniture and shelving systems
Technical Notes
- Carbon content ranges between 0.08% - 0.22%.
- Pre-weld and post-weld heat treatment is generally not required.
- Surface hardness can be increased by carburizing (case hardening).
- Stress relief annealing is recommended after cold forming.
- C20 and C22 grades can be hardened with mild heat treatment.
- Standard length is 3 meters, available up to 6 meters on request.
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Detailed Technical Information and Quotation
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Get Technical SupportWhat is carbon steel?
Carbon steel is steel whose main alloying element is carbon (other elements at residual levels). It is classified by carbon content: low carbon (<0.25% C — formable, weldable), medium carbon (0.25–0.60% C — e.g. C45/1045, a strength/toughness balance) and high carbon (>0.60% C — springs and tools). It is the largest and most economical group of steels.
How carbon content sets the properties
As carbon rises, hardness and tensile strength increase while ductility, toughness and weldability fall. Low-carbon grades (C22, S235) serve deep drawing and welded fabrication; medium-carbon grades (C35–C60, EN 10083-2) are quenched and tempered for shafts, axles and gears; high-carbon grades go into springs, blades and wear parts. C45 is the most common medium-carbon grade: delivered normalized or Q&T, equivalent to AISI 1045. Because hardenability is limited, alloyed Q&T steels (42CrMo4) are preferred for large sections.
Frequently Asked Questions
What is C45 steel and where is it used?+
A medium-carbon Q&T steel with 0.42–0.50% C (equivalent to AISI 1045). The most common grade for shafts, axles, gear blanks and general machine parts.
Low vs medium vs high carbon steel?+
<0.25% C is low (weldable, formable), 0.25–0.60% is medium (heat-treatable, strong), >0.60% is high (very hard; springs/tools).
Can carbon steel be welded?+
Low-carbon grades weld easily. Medium-carbon may need preheat; high-carbon requires special procedures due to cracking risk.
Carbon steel vs alloy steel — what is the difference?+
In carbon steel, properties are set by carbon; in alloy steel, elements like Cr, Mo and Ni add hardenability, toughness and temperature resistance (e.g. 42CrMo4).
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