China Hot Rolled and Cold Drawn Steel Round Bar Suppliers and Factory for Industrial Applications
Specification
| Parameter | Range / Options |
| Diameter | 6 mm – 500 mm (1/4" – 24") |
| Length | 3 m – 12 m (standard: 6m) |
| Tolerance Standards | EN 10277, ASTM A29, JIS G3124 |
Material Standard
| Material Type | Standard | Common Grades |
| Carbon Steel | ASTM A36 / A29 | A36, 1018, 1045, 1215 |
| EN 10083 / 10025 | S235JR, S355JR, C45 | |
| JIS G3101 / G4051 | SS400, S45C, SCM435 | |
| Stainless Steel | ASTM A276 / A484 | 304/L, 316/L, 303, 310S, 630 (17-4PH) |
| EN 10088 | 1.4301, 1.4401, 1.4305 | |
| Alloy Steel | ASTM A29 | 4140, 4340, 8620 |
| EN 10084 | 16MnCr5, 20MnCr5 | |
| Tool Steel | ASTM A681 | O1, D2, A2, M2 |
| Aluminum | ASTM B221 | 6061, 6063, 7075, 2024 |
| Brass / Bronze | ASTM B16 / B124 | C36000, C46400 |
Manufacturing Methods
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Hot Rolling
Steel is heated above recrystallization temperature (approximately 1200°C) and passed through rolling mills. This process produces bars with lower dimensional accuracy and a scaled surface, but offers cost-effectiveness suitable for construction and general applications where finish is not critical.
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Cold Rolling / Drawing
Hot-rolled bars are pulled through dies at room temperature, resulting in superior surface finish, tighter dimensional tolerances, and increased strength. These bars are ideal for precision components and machined parts.
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Peeling
The surface layer is removed by cutting to achieve high dimensional accuracy, a glossy finish, and defect-free surface condition.
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Centerless Grinding
Bars are ground to precise diameter tolerances, providing extreme precision, excellent straightness, and a polished surface for demanding applications.
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Extrusion
Common for aluminum and copper, where billets are forced through a die opening to produce long lengths with consistent cross-sections.
Applications
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Machinery and Mechanical Components
Round bars are extensively used to manufacture shafts, gears, spindles, rollers, pins, and bushings. Their cylindrical shape makes them ideal for rotating parts and components requiring symmetry.
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Automotive Industry
Essential for producing axles, drive shafts, steering components, piston rods, and fasteners. High-strength alloy grades are specified for critical drivetrain applications.
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Construction and Infrastructure
Used as reinforcing bars, column supports, braces, and anchors. Hot-rolled round bars provide reliable strength for structural frameworks.
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Oil and Gas Industry
Employed in downhole tools, valve components, pump shafts, and wellhead equipment. Corrosion-resistant stainless and alloy grades perform in harsh environments.
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Aerospace and Defense
Precision-ground bars serve in landing gear components, turbine shafts, structural connectors, and fasteners where strict tolerances and high reliability are required.
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Manufacturing and Fabrication
Raw material for CNC machining, turned parts, bolts, studs, and custom components across all industries.
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Marine and Offshore
Stainless steel and naval brass round bars provide corrosion resistance for hardware, fittings, shafts, and structural elements in marine environments.
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Energy and Power Generation
Used in turbine components, generator shafts, and nuclear reactor internals, often in specialized high-temperature alloys.
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Medical and Pharmaceutical
Stainless steel round bars are specified for surgical instruments, implants, and medical device components requiring biocompatibility and cleanability.
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Food Processing
Sanitary-grade stainless steel bars serve in equipment frames, conveyor components, and processing machinery where hygiene is critical.
Frequently Asked Questions
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Q What is the standard diameter range available for round bars?
Round bars are available in diameters ranging from 6 mm to 500 mm (1/4" to 24"), with standard lengths from 3 m to 12 m. The most common stock length is 6 m.
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Q What is the difference between hot-rolled and cold-drawn round bars?
Hot-rolled bars are produced at high temperatures and offer cost-effectiveness with slightly lower dimensional accuracy. Cold-drawn bars are processed at room temperature, resulting in tighter tolerances, a smoother surface finish, and higher strength — making them preferred for precision machining applications.
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Q Which round bar material is best for corrosion-resistant applications?
Stainless steel round bars — particularly grades 304, 316, and 316L — are the top choice for corrosion-resistant applications. Grade 316/316L offers superior resistance in marine and chemical environments due to its molybdenum content.
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Q What tolerance standards are used for round bar manufacturing?
Round bars are manufactured to internationally recognized tolerance standards including EN 10277 (European), ASTM A29 (American), and JIS G3124 (Japanese), ensuring dimensional consistency and compatibility with global engineering requirements.
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Q Can round bars be supplied in custom lengths or grades?
Yes. Round bars can be supplied in custom cut lengths and a wide variety of material grades including carbon steel, stainless steel, alloy steel, tool steel, aluminum, and brass/bronze to meet specific project requirements.
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Q What industries commonly use precision-ground round bars?
Precision-ground round bars are widely used in aerospace, medical device manufacturing, automotive, and high-precision machinery industries where extremely tight diameter tolerances, excellent straightness, and superior surface finish are critical requirements.