A36 Q195 Q235 Q345 S355D S355JR SS400 Flat Steel 5160 Spring Steel Flat bar Carbon Steel Flat bar ASTM Hot Dipped Galvanized Flat Steel bar for construction

Flat steel, refers to the steel  which  wide 12-300mm,  thick 3-60mm,the rectangular section and with slightly blunt edge .

Flat steel can be direct use as  finished steel, but also can be use as     metal self-finished material for welded pipe and  laminated sheet.  Application: The flat steel can be used to make hoop iron, tools and machinery parts,or as a building structure, escalator.

Flat steel can be customized according to user needs, fixed thickness, fixed width, fixed length production, for users to save cutting, and reduce processing flow,  it not only help customer save the consumption of labor, materials, but also reduce the processing loss of raw materials,  time saving, labor saving, material saving. Products have been specialized in steel structure manufacturing, machinery manufacturing, automotive industry, mining machinery, lifting machinery and other industries.

. Flat steel according to its shape is divided into two kinds: flat spring flat steel and single double slot spring flat steel.

Hot rolled spring flat steel is mainly used for manufacturing automobile, tractor, railway transportation and other machinery leaf spring.

Flat Steel Bar: Specifications, Properties & Applications

1. Basic Definition & Classification

• Production Process: Hot-Rolled Flat Bar (cost-effective, widely available) / Cold-Finished Flat Bar (higher precision, smoother surface).
• Material Grade: Carbon steel (e.g., A36, 1018, Q235), alloy steel (e.g., 4140), stainless steel (e.g., 304, 316), and high-strength structural steel.
• Surface Finish: Hot-rolled black (mill scale), pickled & oiled (P&O), galvanized (hot-dip or electro-galvanized), polished, or painted.

2. Key Specifications

3. Mechanical Properties (Typical for A36 Flat Bar)

• Yield Strength: ≥ 250 MPa (36,000 psi)
• Tensile Strength: 400–550 MPa (58,000–79,800 psi)
• Elongation: ≥ 20% (in 200mm)
• Hardness: ≤ 137 HB (hot-rolled)
• Weldability: Excellent (compatible with arc welding, MIG, TIG, and resistance welding).
• Machinability: Good for drilling, cutting, bending, and punching (cold-finished bars offer better precision for machining).

4. Main Applications

4.1 Construction & Infrastructure

• Structural Reinforcement: Used as bracing, lintels, and edge reinforcement for concrete slabs, beams, and columns.
• Supports & Frames: Fabrication of brackets, pipe supports, and structural frames for buildings, bridges, and industrial platforms.
• Architectural Details: Handrails, stair stringers, and decorative trim (galvanized or polished finishes for corrosion resistance).

4.2 Machinery & Equipment Manufacturing

• Machine Bases & Frames: Stiffeners and structural components for motors, pumps, conveyors, and industrial machinery.
• Fabricated Parts: Custom jigs, fixtures, and workbenches (ease of machining and welding makes it ideal for prototypes and production parts).
• Shafts & Gears: Cold-finished flat bars are machined into small shafts, gears, and linkages for light-duty equipment.

4.3 Automotive & Transportation

• Vehicle Frames: Reinforcement bars for truck bodies, trailers, and agricultural machinery.
• Chassis Components: Brackets, mounts, and cross members (high-strength grades like 4140 for heavy-duty applications).

4.4 Industrial & Commercial Uses

• Manufacturing: Base plates, spacers, and fastener components (stainless steel flat bars for corrosive environments like chemical plants).
• Storage & Logistics: Shelving, racking, and pallet supports (high load-bearing capacity with cost-effectiveness).
• Electrical & HVAC: Supports for electrical conduits, HVAC ductwork, and cable trays.

4.5 General Engineering

• Repair & Maintenance: Replacement parts for machinery, industrial equipment, and infrastructure.
• Custom Fabrication: Art installations, signage, and DIY projects (versatile dimensions and easy processing).

5. Standards Compliance

• ASTM A36/A36M (Carbon Structural Steel)
• ASTM A1011 (Hot-Rolled Sheet and Strip Steel)
• EN 10058 (Flat Steel Bars for General Engineering)
• GB/T 702 (Chinese Standard for Hot-Rolled Steel Bars)
• JIS G 3131 (Japanese Standard for Carbon Steel Flat Bars)

6. Advantages

• Versatility: Suitable for load-bearing, reinforcement, and fabrication across industries.
• Cost-Effective: Lower production costs compared to shaped profiles (e.g., angles, channels).
• Easy Processing: Can be cut, welded, drilled, bent, and machined with standard tools.
• Wide Availability: Stocked in various sizes and materials globally.

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