Carbon steel round bars are a type of steel with a circular cross-section. They are made of carbon structural steel and are widely used in machinery manufacturing, construction, hardware, and other fields. Based on carbon content, they can be divided into low-carbon steel, medium-carbon steel, and high-carbon steel, each suitable for different applications. We will now focus on medium-carbon steel C45 round bars.
C45 round bars are a type of non-alloy medium-carbon steel and a general-purpose carbon engineering steel. C45 steel possesses excellent comprehensive mechanical properties, high strength, good machinability, and moderate plasticity and toughness. Due to its excellent performance and high cost-effectiveness, C45 grade round bars, plates, flat bars, and square bars are used in the quenching and tempering of axles, bolts, forged connecting rods, crankshafts, torsion bars, light gears, guide rods, screws, forgings, wheels and tires, shafts, sickles, axes, knives, woodworking drill bits, hammers, etc.
Mechanical properties of C45 round steel bars:
Mechanical properties in quenched and tempered state
| 直径d (mm) | 厚度 t (mm) | 0.2% 屈服强度 (N/mm 2 ) | 抗拉强度 (N/mm 2 ) | 伸长率 A 5 (%) | 减少 Z (%) |
| <16 | <8 | 分钟。490 | 700-850 | 分钟。14 | 分钟。35 |
| <17-40 | <8<=20 | 分钟。430 | 650-800 | 分钟。16 | 分钟。40 |
| <41-100 | <20<=60 | 分钟。370 | 630-780 | 分钟。17 | 分钟。45 |
Mechanical properties under normalized conditions
| 直径d (mm) | 厚度 t (mm) | 0.2% 屈服强度 (N/mm 2 ) | 抗拉强度 (N/mm 2 ) | 伸长率 A 5 (%) |
| <16 | <16 | 分钟。390 | 分钟。620 | 分钟。14 |
| <17-100 | <16<=100 | 分钟。305 | 分钟。305 | 分钟。16 |
| <101-250 | <100<250 | 分钟。275 | 分钟。560 | 分钟。16 |
DIN C45 round bar steel grade heat treatment
| 锻造或热轧： | 1100 – 850°C |
| 标准化： | 840 – 880°C/空气 |
| 软退火： | 680 – 710°C/炉 |
| 硬化： | 820 – 860°C/水，油 |
| 回火： | 550 – 660°C/空气 |
One of the main advantages of C45 carbon steel bars is their excellent machinability. This characteristic makes them easy to cut, form, and finish, making them ideal for precision engineering. Furthermore, C45 steel has good hardenability, meaning its mechanical properties can be further enhanced through heat treatment. This versatility makes it suitable for a wide range of applications, from simple structural components to complex mechanical parts.
In summary, C45 round steel bars are a versatile and durable material that can meet the needs of various industries. With its standard size range, excellent machinability, and affordable price, C45 round steel bars are an ideal choice for manufacturers looking to improve product performance and lifespan.
Post time: Apr-24-2026
