Hot rolled steel bar are long cylindrical-section steel products with high strength, toughness, excellent machinability, and heat-treatment properties. Widely used in machinery, automotive, energy, rail transit, shipbuilding, construction, and hardware industries, we offer hot-rolled, cold-drawn, and forged round bars in carbon steel, alloy steel, stainless steel, tool steel, and specialty alloys. Manufactured to international standards, our steel bars deliver superior dimensional accuracy, surface finish, and mechanical performance-making them essential raw materials for industrial manufacturing.
Key Features
Standards:
Chinese Standards:
GB/T 702-2017 (Dimensions, Tolerances for Hot-Rolled Bars)
GB/T 700-2006 (Carbon Structural Steels)
GB/T 699-2015 (Quality Carbon Steels)
GB/T 3077-2015 (Alloy Structural Steels)
GB/T 1220-2007 (Stainless Steel Bars)
GB/T 1299-2014 (Tool & Die Steels)
International Standards:
ASTM A29/A29M (General Requirements for Steel Bars)
ASTM A108 (Cold-Finished Carbon Steel Bars)
ASTM A322 (Alloy Steel Bars)
JIS G 4051, G 4105 (Japanese Steel Bars)
EN 10083-2 (Quenched & Tempered Steels, e.g., 42CrMo4)
DIN 1013 (German Round Bar Standard)
Industry Codes:
JB/T 5000.8-2007 (Forgings for Heavy Machinery)
Materials:
Carbon Steels:
Q235A/B/C (general structural use)
Q355B (high-strength structure)
Quality Carbon Steels:
20#, 35#, 45# (shafts, gears, connectors, heat-treatable)
Alloy Steels:
40Cr, 35CrMo, 42CrMo (high-strength shafts, fasteners)
20CrMnTi (carburizing gear steel)
Stainless Steels:
304/304L, 316/316L (corrosion-resistant)
1Cr13, 2Cr13 (martensitic, for knives, valves)
Tool & Die Steels:
T8, T10 (carbon tool steels)
Cr12, H13 (cold/hot work die steels)
Specialty Steels:
Spring Steels: 65Mn, 60Si2Mn
Bearing Steel: GCr15
High-Temp Alloys: GH4169 (Ni-based, aerospace)
Dimensions:
Diameter:
Hot-Rolled: Φ10–300mm
Cold-Drawn: Φ6–100mm (high precision)
Forged: Φ80–800mm (large diameter, high density)
Length:
Hot-Rolled/Cold-Drawn: 6m, 9m, 12m; up to 18m
Forged: 1–6m (custom)
Tolerances:
Hot-Rolled: h11–h13 (GB/T 702)
Cold-Drawn: h8–h10 (precision machining)
Surface Finish:
Hot-Rolled: as-rolled, pickled, peeled
Cold-Drawn: bright (ready for machining)
Forged: turned or ground
Applications:
Machinery: Shafts, gears, connecting rods
Automotive: Crankshafts, axles, steering knuckles
Energy: Turbine shafts, wind power spindles, valve stems
Rail Transit: Wheel axles, traction pins
Marine: Rudder stocks, propeller shafts
Construction: Anchor bolts, prestressed rebar
Hardware: Drill bits, taps, tools
Oil & Gas: Drill collars, sucker rods
Certifications & Approvals:
Classification Society Certifications:
CCS, ABS, DNV, LR, BV, NK
Provide: Type Approval, MTC 3.1/3.2, Factory Survey, CoC
Owner & Engineering Company Approvals:
ISO 9001, ISO 14001, ISO 45001
PED 2014/68/EU, NORSOK M-650/M-601
Approved by CNPC, Sinopec, CNOOC, State Grid, CRRC, CSSC, Huawei, Shell, ExxonMobil, BP, Total, Chevron, Siemens, GE
Common Customer Questions (Q&A Format)
Q: What is the difference between hot-rolled and cold-drawn bars?
A: Hot-rolled bars are larger in size and lower in cost; cold-drawn bars have higher precision, smoother surface, and are ready for machining.
Q: What is the difference between 45# and 40Cr?
A: 45# is medium-carbon steel; 40Cr is alloy steel with Cr, offering higher strength, hardenability, and wear resistance.
Q: Do you offer custom sizes?
A: Yes, we can customize diameter, length, tolerance, and processing (chamfering, grooving, drilling, heat treatment).
Q: Do you provide heat treatment?
A: Yes, options include normalizing, annealing, quenching & tempering, carburizing, nitriding.
Q: How is weldability?
A: Low-carbon steels (Q235, 20#) weld well; alloy steels (40Cr, 42CrMo) require preheating (150–300°C) to prevent cracking.
Q: Do you provide Material Test Certificates (MTC)?
A: Yes, MTC 3.1/3.2 provided per batch with heat number, chemistry, tensile/impact/hardness data.
Q: What is the maximum single length?
A: Up to 18m for rolled bars; forged bars up to 6m; longer pieces can be segmented.
Q: Suitable for low-temperature service?
A: Yes, we supply steels with -40°C impact testing for arctic or offshore use.
Q: How is dimensional accuracy ensured?
A: Hot-rolled bars comply with GB/T 702; cold-drawn bars achieve ±0.05mm tolerance via precision drawing.
Q: What is the lead time?
A: Standard: 7–15 days; custom: 20–45 days, depending on complexity and heat treatment.
Q: Can it be used in pressure equipment?
A: Yes, we supply PED/ASME-compliant materials with pressure equipment certification.
Q: Do you offer cutting services?
A: Yes, sawing, plasma, or laser cutting available for length customization.
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