In industrial applications, carbon steel round bars are one of the most versatile and widely used materials. We focus on producing high-quality carbon steel round bars to meet a variety of different needs.
Classification of Carbon Steel Round Bars
1. Low-Carbon Steel Round Bars. Representative grades: Q195, Q235, 10#, 20#, 1018, 1020, etc. The most commonly used carbon steel round bar grades internationally include ASTM A36.
ASTM A36 is a low-carbon steel widely used in structural engineering due to its excellent weldability and machinability.
Core characteristics of low-carbon steel:
* Excellent plasticity and toughness: Soft material, easy to bend, stamp, stretch, and cold head; not easily broken during cold working.
* Excellent weldability: Suitable for arc welding, gas shielded welding, and spot welding; welds are crack-free and do not harden embrittlement.
* Easy to machinable: Low hardness; smooth turning, milling, drilling, and tapping; low tool wear.
* Suitable for carburizing heat treatment: For example, 1018/1020 low-carbon steel can be directly carburized and quenched to achieve surface wear resistance and good core toughness.
2. Medium carbon steel round bars. Representative grades: 35#, 45#, 55#, etc.
Core characteristics of medium carbon steel:
* Higher strength and hardness: Good overall mechanical properties; after tempering, it achieves a balance of strength and toughness.
* Good machinability: Good hot working and cutting performance, but poor weldability, requiring preheating and other processes.
* Can be heat-treated for strengthening: Supports quenching and tempering treatment, significantly improving hardness and wear resistance.
3. High carbon steel round bars. Representative grades: T8, T10, T12, etc., tool steels.
Core characteristics of high carbon steel:
* Extremely high hardness: Can be hardened and tempered, commonly used in tool manufacturing.
* Excellent wear resistance: Suitable for high-wear conditions.
* Lower plasticity and toughness: More difficult to process.
Commonly used dimensions for carbon steel round bars.
Different grades of carbon steel may have slightly different common round bar dimensions:
| steel grades | Common diameter range | Typical application scenarios |
| 1018 / 20# | Φ3.0mm – 300mm | General mechanical parts such as shafts, pins, rods, and sprocket assemblies |
| 45# / 1045 / S45C | Φ6mm – 460mm | Most commonly used, for manufacturing gears, shafts, molds, etc. |
| C45 / 1.1191 | Φ8mm – 300mm | Corresponding to 45# steel, used for shafts, axles, gears, etc. |
| 25# | Φ18mm – 260mm | Used in machinery manufacturing, building decoration and other fields. |
| 65# | All specifications are available | Used in the manufacture of high-strength parts such as springs and wire ropes. |
| Q235 | Φ10mm – 300mm | Used in building structures, machine tools, etc. |
| 1.0145 (S275J2) | Φ4.0mm – 350mm | Used for structural components in buildings, machinery, vehicles, etc. |
Applications of Carbon Steel Round Bars
Carbon steel round bars have a wide range of applications across various industries. In the construction industry, they are commonly used to reinforce concrete, manufacture structural components, and produce machine parts. The automotive industry also relies on carbon steel round bars to produce axles, drive shafts, and other critical components requiring high strength and durability. Furthermore, these round bars are essential in the manufacture of tools, fasteners, and fittings, making them a primary material in the metalworking industry.
In summary, carbon steel round bars are fundamental components across various industries, boasting advantages such as wide application, high strength, and high reliability. Jindalai Steel Group Co., Ltd., as a trustworthy supplier of high-quality carbon steel round bars, is committed to meeting the diverse needs of its customers. By understanding customer requirements, we continuously improve our service levels.
Post time: Aug-26-2026
