Flat Bars & Steel Bars – Fundamental Profiles for Machinery Manufacturing & Structural Support
We offer a full range of flat bars and steel bars (round bars/square bars/hex bars). Flat bars refer to steel with a rectangular cross-section, where the width is much greater than the thickness; steel bars include round bars, square bars, hexagonal bars, and other cross-sectional shapes. These products are characterized by simple cross-sectional shapes, excellent processing performance, and wide application range, making them fundamental materials in machinery manufacturing, hardware tools, building structures, automotive parts, and other fields. We manufacture strictly according to international standards and support customized sizes, surface treatments, and deep processing services.
1.Product Range, Sections & Standards
Flat bars and steel bars are mainly classified into three categories according to manufacturing processes: hot-rolled, cold-drawn (cold-extruded), and forged. They can also be classified according to cross-sectional shapes such as flat bars, round bars, square bars, and hexagonal bars.
- Flat Steel Bars: Flat steel bars have a rectangular cross-section, with a width significantly greater than their thickness, making them ideal for mechanical parts, grating, and hardware.
- Hot-Rolled Flat Steel Bars: Hot-rolled flat steel bars are produced by heating and rolling steel billets. They have a hot-rolled finish, excellent mechanical properties, and are the most widely used flat steel product.
Standards:
GB: GB/T 702, GB/T 704
ASTM: ASTM A36, A572 Gr.50
EN: EN 10058, S235JR, S355JR
JIS: JIS G3101 (SS400), JIS G3192
DIN: DIN 1017
Main Materials:
Carbon Steel Series: Q195, Q215, Q235, Q275
Low Alloy High Strength: Q345, Q355, Q390
ASTM: ASTM A36, A572 Gr.50, A992
EN: S235JR, S275JR, S355JR
JIS: SS400, SS490, SS540
Size Range:
Rolled Flat Steel: Thickness 8-60mm × Width 20-150mm
Forged Flat Bars: Thickness 60-800mm × Width 120-1500mm
Standard Range: Thickness 1.5-30mm × Width 10-200mm
Length: 6m, 9m, 12m or custom length as required
- Cold Drawn Flat Bars
Cold drawn flat bars are produced through a cold drawing process, resulting in high dimensional accuracy and a smooth surface, suitable for precision mechanical parts.
Standards: GB/T 905, EN 10278
Material Series: Q235, 45#, 40Cr, 20Cr
Specifications: Customized according to customer requirements, tolerances up to h9-h11 grade
- Stainless Steel Flat Bars
Stainless steel flat bars have excellent corrosion resistance and an attractive surface, suitable for chemical, food machinery, and decorative industries.
Standards: ASTM A276, ASTM A484, EN 10088, GB/T 1220
Main Materials:
300 Series: 304, 304L, 316, 316L
200 Series: 201, 202
400 Series: 410, 420, 430
Duplex Steel: 2205, 2507
Specification Range: Thickness 1.5-16mm × Width 20-600mm
Surface Finish: Hot-rolled pickled, cold-drawn bright, polished, brushed
- Spring Flat Bars
Spring flat bars are specifically designed for automotive leaf springs and suspension systems, exhibiting excellent fatigue performance and elasticity.
Standards:
National Standards: GB/T 1222, GB/T 33164.1
Main Materials:
Premium Series: 28MnSiB, 50CrVA 52CrMoV4
High-Performance Series: FAS3550 High-Performance Spring Steel
Special Properties: Resistant to -40℃ low-temperature impact, fatigue life up to 4 times the national standard
- Galvanized Flat Bars
Galvanized flat bars use hot-rolled flat steel as the base material and undergo hot-dip galvanizing treatment, providing excellent corrosion resistance.
Specifications: 25×3mm, 30×3mm, 40×4mm, 50×5mm, and other common specifications
Zinc Coating: Double-sided galvanizing amount 200-600g/m²
Applications: Power grounding, photovoltaic brackets, outdoor guardrails
2.Steel Bars (Round/Square/Hex)
Steel bars include round bars, square bars, hexagonal bars, and other cross-sectional shapes, and are a major raw material for machining.
- Hot Rolled Round Bars
Hot rolled round bars are the most common steel bar product, widely used in the processing of shafts, gears, bolts, and other mechanical parts.
Execution Standards: GB/T 702, ASTM A29, EN 10060, JIS G3191
Main Materials:
Carbon Structural Steel: Q235, 20#, 35#, 45#
Alloy Structural Steel: 40Cr, 20Cr, 20CrMnTi, 35CrMo, 42CrMo
Stainless Steel: 304, 316L, 410, 420, 431
Tool Steel: Cr12MoV, H13, D2
Ultra-High Strength Steel: 300M, 18Ni series, 30Cr3SiNiMoVA
High Temperature Alloy: GH4169, GH4698, GH4141
Corrosion-Resistant Alloy: UNS N08825, UNS N010276
Size Range:
- Regular Round Bar: Φ12-800mm Precision Round Bars: Φ12-600mm
- Extra Long Round Bars: Customizable according to customer requirements
Delivery Conditions: Hot-rolled, Annealed, Normalized, Quenched and Tempered
- Cold Drawn Round Bars: Cold-drawn round bars offer high dimensional accuracy and a smooth surface, suitable for direct machining on automatic lathes.
Standards: GB/T 3078, EN 10277, ASTM A108
Material Series: Q235, 45#, 40Cr, 20Cr
Precision Grade: h8-h11
Specification Range: Φ3-80mm
- Square Bars: Square bars have a square cross-section and are used for mechanical parts, molds, building structures, etc.
Specification Range: 5×5mm – 200×200mm
Material Series: Same as round bar material
- Hexagon Bars: Hexagonal bars are mainly used to manufacture nuts, bolts, tools, etc., facilitating wrench clamping.
Specifications: S5-S100mm across flats
Material: Carbon steel, alloy steel, stainless steel
Customization: Any size, no mold required
- Key Differentiators
✔ End-to-End Supply Chain Advantage, Controllable Quality Throughout. We leverage our advantages across the entire process, from steelmaking and continuous casting to rolling, ensuring complete control over product quality.
✔ Diverse Standards Coverage, Global Market Access
We support major global industrial standards, and our products comply with Chinese national standards (GB), American standards (ASTM), European standards (EN), Japanese standards (JIS), and German standards (DIN). Whether your target market is North America, Europe, Southeast Asia, or the Middle East, we can provide products that meet local standards.
✔ High-precision dimensional control, reducing subsequent processing
Advanced rolling mills and precision cold drawing processes ensure strict control of dimensional tolerances within standard ranges.
✔ Excellent low-temperature impact performance, adaptable to harsh environments.
✔ Diverse material selection, covering all application scenarios
Customized material solutions are provided according to application scenarios:
General mechanical parts: Q235/45#, high cost-performance ratio
Automotive leaf springs: 28MnSiB/50CrVA/52CrMoV4, excellent fatigue performance
Die manufacturing: Cr12MoV/H13/5CrNiMo, meeting tooling requirements
Corrosive environments: 304/316L/2205 stainless steel, excellent corrosion resistance
High-temperature applications: GH4169 high-temperature alloy, temperature resistance up to 1000℃
✔ One-stop processing service, from materials to finished products: Providing services from materials to processing.
Material Guarantee: Relying on resources from major domestic and international steel mills, quality is guaranteed, and materials are traceable.
Complete Processing: A full range of processes including slitting, shearing, laser cutting, wire drawing, and edge planing.
High Efficiency: Leveling, straightening, and edge deburring are completed in one integrated process, saving costs for customers.
- Quality Assurance
1) We have established a complete quality control system from raw materials to finished product delivery to ensure that every batch of flat steel and steel bars meets international standards. Full-Process Testing System
Raw Material Inspection: 100% spectral analysis of material chemical composition to ensure that elements such as C, Si, Mn, P, and S meet standards.
Carbon Equivalent Control: Strict control of CEV value to ensure weldability and mechanical properties.
Process Control: Full monitoring of heating temperature, rolling force, and cooling rate.
Dimensional Accuracy Control: Width, thickness, and straightness strictly controlled according to standards.
2) Mechanical Property Testing
Tensile, bending, and impact tests are conducted batch by batch to ensure that yield strength, tensile strength, elongation, and impact energy meet standards:
Spring Flat Steel: Strictly in accordance with the national standard GB/T 33164.1 “Spring Steel for Automotive Suspension Systems”
Stainless Steel Flat Steel: Tensile strength ≥485MPa, hardness 183 HB
Tool Steel Flat Steel: Hardness 201-255HB, suitable for mold and mechanical parts manufacturing. Surface Quality Assurance
Hot-rolled flat steel: Localized oxidation is permissible, but defects such as cracks, scabs, and folds are prohibited.
Cold-drawn flat steel: High surface finish, no oxide layer, suitable for direct precision machining.
Stainless steel flat steel: Polishing, brushing, and other surface treatments are available to meet decorative and food-grade requirements.
3) International Certifications
ISO 9001:2015 Quality Management System
CE Certification (EN Standard Products)
ASTM Certification (Meets US Standards)
JIS Certification (Japanese Industrial Standards)
BV/SGS Third-Party Inspection Agency Accreditation
EN 10204 3.1/3.2 Material Certificates Available
4) Digital Traceability System
Based on a robust material platform, the chemical corrosion resistance and mechanical properties of the materials are highly reliable and traceable, ensuring no counterfeits. Each batch of products can be traced back to the raw material furnace number, production batch, and quality inspection records, ensuring that quality issues are traceable and manageable.
- After-Sales & Technical Support
1) 100% After-Sales Quality Guarantee. We promise a 100% after-sales guarantee for product quality and quantity.
2) Professional Technical Support: Material selection consultant service, customized production based on user needs, helping to reduce subsequent cutting processes and lower labor and material costs.
3) Logistics Guarantee: Professional Packaging: Protected by sheet metal at both ends, waterproof packaging, suitable for long-distance sea freight.
Multiple Transportation Modes: Handles bulk carriers, containers, rail, and road transport.
Standardized Packaging: Standardized packaging, convenient logistics, and traceable processes comprehensively guarantee customer experience.
- OEM Customization Services
✔ Size Customization: Fixed-length cutting: Cutting to any length according to customer requirements, standard 6-12m, supports ultra-long flat steel up to 14 meters.
Non-standard Specifications: Supports customization of special widths, thicknesses, and lengths.
Precision Requirements: Meets customer requirements for high precision, hardness, straightness, flatness, and torsion.
Minimum Order Quantity: OEM orders start from 20 tons.
✔ Material Customization: Customized materials for different application scenarios:
High-strength Applications: Customizable high-strength flat steel with yield strength of 700-960MPa. Corrosion-resistant environments: Customizable with 304/316L/2205/2507 stainless steel
High-temperature applications: Customizable with high-temperature alloys such as GH169 and C276
Special properties: Customizable with non-magnetic properties, tensile strength, yield strength, elongation, and solution treatment requirements
Customized spring steel: Spring steel composition can be adjusted according to customer’s heat treatment process, creating a customized “homemade” solution
✔ Customized surface treatment
Delivery condition: Hot-rolled black, peeled, pickled, shot peening, cold-drawn bright
Surface treatment: Polishing, wire drawing, galvanizing, passivation
Special requirements: Surface coating or anti-corrosion treatment can be applied according to customer requirements
Processing capabilities:
Slitting flat steel: Width 20-600mm, Thickness 1.5-16mm
Sheared flat steel: Flat steel produced by shearing process
Laser-cut flat steel: Laser-cut flat steel, high precision, suitable for irregularly shaped parts
Wire-brushed flat steel: Surface wire-brushed finish, beautiful and durable Leveling and Straightening: Leveling, straightening, and edge deburring are completed in one integrated process.
Other Processing:
Bending/Welding: Bending, welding, uncoiling, punching
Machining: CNC machining, centerless grinding
Heat Treatment: Annealing, normalizing, tempering, solution treatment
✔ Custom Packaging and Labeling
Export Packaging: Securely bundled, with sheet metal protection at both ends, and wrapped in waterproof cloth.
End Protection: To prevent damage during transportation.
Custom Labeling: Labels are affixed according to customer requirements (project name, furnace batch number, component number, QR code, etc.).
