Carbon steel bars are used in machinery manufacturing, construction, automotive parts, and general engineering applications. We supply round bars, flat bars, and square bars in grades including AISI 1020, 1045, 4140, 4340, GB 42CrMo, 40Cr, Q235B, and Q345B. Round bar diameter range from 10mm to 500mm. Flat bar thickness from 5mm to 100mm. Available in hot rolled, cold drawn, forged, and peeled conditions. Complete material certification provided.
Q345B is a Chinese standard low-alloy high-strength structural steel flat bar with minimum yield strength of 345 MPa, offering 50% higher strength than Q235B with excellent weldability. Width 20-500mm, thickness 3-100mm, ideal for bridges, heavy machinery, and structural fabrication.
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Q235B is a widely used carbon structural steel flat bar per GB/T 700, equivalent to ASTM A36 / S235JR / SS400. Offers minimum 235 MPa yield strength, excellent weldability, and superior cost-efficiency. Width 10-300mm, thickness 3-60mm, ideal for structural frames, fabrication, and construction.
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GB 40Cr is a chromium alloy steel round bar per GB/T 3077, equivalent to AISI 5140 / EN 41Cr4 / SCr440. Offers higher strength than carbon steel, reliable hardenability, and excellent induction hardening response. Diameter 10mm-500mm, ideal for shafts, gears, bolts, and medium-duty mechanical components.
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GB 42CrMo is a chromium-molybdenum alloy steel round bar per GB/T 3077, equivalent to AISI 4140 / EN 42CrMo4 / SCM440. Offers high strength, excellent hardenability, superior toughness, and good fatigue resistance. Diameter 16mm-600mm, available in hot rolled, Q&T, and nitrided conditions for oil & gas, wind power, and heavy machinery.
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AISI 4340 is a premium Ni-Cr-Mo alloy steel round bar with the highest hardenability, extreme tensile strength (up to 1800 MPa), outstanding low-temperature toughness, and superior fatigue resistance. Diameter 20mm-600mm, VAR/ESR grades available for aerospace and defense applications.
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AISI 1045 is a versatile medium-carbon steel round bar with higher strength and hardness than low-carbon grades. Diameter from 6mm to 500mm, available in hot rolled, cold drawn, and Q&T conditions for shafts, gears, bolts, and heavy-duty machinery components.
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AISI 1020 is a versatile low-carbon steel round bar with excellent weldability, good machinability, and the ability to be case-hardened. Diameter from 6mm to 500mm, available in hot rolled, cold drawn, and peeled conditions for shafts, machinery components, and welded fabrication.
View Details →Overview of Q345B Carbon Steel Flat Bar Q345B is a widely used Chinese standard low-alloy high-strength structural steel flat bar specified under GB/T 1591 standard. With a minimum yield strength of 345 MPa and tensile strength of 470-630 MPa, Q345B…
Overview of Q235B Carbon Steel Flat Bar Q235B is one of the most commonly used carbon structural steel flat bar grades in China and the Asia-Pacific region, specified under the Chinese national standard GB/T 700 (Carbon Structural Steels). The designation…
Overview of GB 40Cr Alloy Steel Round Bar GB 40Cr is a widely used chromium alloy structural steel round bar specified under the Chinese national standard GB/T 3077 (Alloy Structure Steels). With carbon content of 0.37-0.44% and chromium content of…
Overview of GB 42CrMo Alloy Steel Round Bar GB 42CrMo is one of the most widely used and trusted alloy steel round bar grades in China and global markets, specified under the Chinese national standard GB/T 3077 (Alloy Structure Steels).…
Overview of AISI 4340 Alloy Steel Round Bar AISI 4340 is a premium nickel-chromium-molybdenum (Ni-Cr-Mo) alloy steel round bar recognized as one of the highest-strength, most versatile through-hardening alloy steels available in global engineering. With carbon content of 0.38-0.43%, nickel…
Overview of AISI 1045 Carbon Steel Round Bar AISI 1045 is a widely used medium-carbon steel round bar specified under AISI/SAE 1045 standard with carbon content typically 0.43-0.50%. This grade provides significantly higher strength and hardness than low-carbon grades like…
Overview of AISI 1020 Carbon Steel Round Bar AISI 1020 is one of the most commonly used low-carbon steel round bars in global manufacturing and engineering applications. Specified under AISI/SAE 1020 standard with carbon content typically 0.17-0.23%, this grade offers…
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