High-Quality 4140/4130/4340 Carbon Alloy Steel Round Bars from China Suppliers | Factory Direct, Hot-Rolled/Cold-Rolled
Precision-machined carbon steel round bars are designed to meet structural load-bearing and precision machining requirements, encompassing a variety of grades:
Low-carbon steel (1018, Q235B, A36) — Excellent cold formability, weldability, and ductility, ideal for components requiring bending, stamping, or general structural support.
Medium-carbon steel (1045, 45#, 20#) — Balances machinability and heat-treatable strength, achieving tensile strength up to 600 MPa after quenching and tempering; suitable for load-bearing shafts and mechanical parts.
High-carbon steel (40Cr, 45Mn2) — Incorporates alloying elements, enhancing hardness and wear resistance; ideal for gears and tool blanks.
We offer flexible, project-specific specifications: diameters ranging from 3 mm (micro precision pins) to 500 mm (heavy-duty structural bars), standard lengths up to 6 meters, and custom cutting, chamfering, or threading services are available.
Manufacturing processes are matched to steel grades — large-diameter structural bars are hot-rolled (ensuring grain refinement and toughness), while small-diameter precision bars are cold-drawn (achieving tight dimensional tolerances of ±0.03 mm and a smooth surface with Ra≤1.6μm).
Optional surface treatments include blackening (black anodizing), phosphating (rust prevention), or polishing (meeting aesthetic and friction reduction requirements).
These round bars play a crucial role across industries:
Products fully comply with GB/T 702, ASTM A108, and ISO 683-1 standards. Each batch undergoes rigorous quality verification including ultrasonic testing, tensile/impact testing, and hardness (HB/HRC) measurement. We offer bulk supply, just-in-time delivery, and technical consulting services.
Product Name |
AISI 4140 Flat Angle 1060 C45 CK45 1095 1020 A36 Q235 SAE 1016 1084 Low Round Carbon 1045 1050 1055 Steel Bar |
Standard |
ASTM A106, ASTM A53, API 5L Gr.B, DIN17175, DIN1629 |
Outer Diameter |
20mm – 610mm |
Wall Thickness |
4mm – 70mm |
Dia Tolerance |
Controlled within standard: OD ±1%, WT ±10% |
Materials |
10#, 20#, 45#, 16Mn, A106 (B, C), A53 (A, B), API J55, API K55, Q235, Q345, ST35.8, ST37, ST42, ST45, ST52 |
Inspection |
ISO, BV, SGS, MTC |
Packing |
Waterproof paper and steel strip packed. Standard Export Seaworthy Package. Suitable for all kinds of transport, or as required. |
Supply Ability |
1,000 metric tons / month |
MOQ |
5 metric tons; sample order accepted |
