Square Steel Bar

Product Overview

Square steel bars are solid metal bars with a square cross-section, produced via hot rolling, cold drawing, or forging. Used primarily as structural members or machined into discrete components, these bars provide high dimensional stability and uniform mechanical properties across standard industrial grades.
Our production operations utilize continuous rolling mills and multi-stage drawing benches capable of maintaining tight cross-sectional tolerances, straightness controls within 1.5 mm/m, and crack-free surfaces verified through automated eddy current testing. We supply carbon, alloy, and stainless steel square bars tailored to direct fabrication or secondary CNC machining operations.

Hot Rolled Square Bar
Hot Rolled Square Bars are hot-formed carbon and alloy steel profiles produced via high-temperature rolling mills. Designed for structural frameworks, machinery parts, and further processing (such...
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Cold Drawn Square Bar
Cold Drawn Square Bar is manufactured by cold-drawing hot-rolled wire rods or carbon/alloy steel bars through a tungsten carbide die at room temperature. This cold-working process alters the grain...
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Tool Steel Square Bar
Tool steel square bars provide raw stock material optimized for high wear resistance, compressive strength, and dimensional stability under thermal stress. Supplied in hot-rolled, forged, or...
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Stainless Steel Square Bar
Hot-rolled and cold-drawn stainless steel square bars supplied in standard and custom lengths. Produced via precision rolling or cold drawing followed by solution annealing, intended for CNC...
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Alloy Steel Square Bar
Industrial-grade alloy steel square bars supplied in hot-rolled, forged, or cold-drawn conditions. Engineered for high-load mechanical components, structural frameworks, and heavy-machinery parts...
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Carbon Steel Square Bar
Carbon steel square bars are solid hot-rolled or cold-drawn steel profiles featuring 90-degree sharp or slightly rounded corners. Engineered for high tensile strength, machinability, and...
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Technical Specifications

Parameter	Specification Range
Size Range	10 mm × 10 mm to 300 mm × 300 mm (3/8 in to 12 in)
Standard Lengths	3 m, 6 m, or cut-to-length as specified (± 5 mm)
Material Grades	Carbon Steel: AISI 1018, 1045, 1020 Alloy Steel: AISI 4140, 4340, 8620 Stainless Steel: 304/304L, 316/316L
Execution Standards	ASTM A29, ASTM A108, EN 10059, DIN 178, JIS G4051
Surface Conditions	Hot-rolled (black, scale conditioned), Cold-drawn (Ra ≤ 1.6 μm), Turned/Peeled and Polished (Ra ≤ 0.8 μm)
Straightness Tolerances	≤ 1.5 mm/m (Standard), ≤ 0.75 mm/m (Precision)
Mill Test Certificate	EN 10204 3.1 chemical & mechanical test report included per heat number

Product Advantages

Dimensional Uniformity:

Cold-drawn variants maintain strict cross-sectional tolerances (h11/h12), reducing preparatory setup time and eliminating secondary sizing passes on CNC milling and lathe equipment.

Consistent Machinability:

Controlled sulfur ranges (0.020% to 0.040%) and fine-grain practice in electric arc furnaces (EAF) minimize tool wear during high-feed milling operations.

Straightness Stability:

Thermal stress-relieving post-drawing prevents internal residual stress warping during subsequent customer laser cutting or deep pocket milling.

Traceability:

Each bar is heat-stamped and color-coded with heat numbers corresponding directly to the provided EN 10204 3.1 certificate.

Applications

Machine Building: Transmission shafts, gears, slide guides, and structural frames for industrial machinery.

Automotive & Heavy Equipment: Axle components, steering linkages, agricultural implement brackets, and chassis reinforcement bars.

Structural Fabrication: Support columns, grating frames, architectural embeds, and plant maintenance brackets.

Fastener & Hardware Production: Cold-headed or machined nuts, bolts, specialized anchor studs, and connection hardware.

Customization & Processing

Custom Cutting:

Precision cold-sawing and band-sawing services providing cut lengths down to ± 1 mm tolerance with burr-free, square-cut ends.

Surface Treatments:

Shot-blasting to remove mill scale, centerless grinding for tight diameter/width tolerances, and rust-preventive oil coating.

Thermal Processing:

Annealed (SRA), normalized, or quenched and tempered (Q&T) conditions to achieve specific hardness levels (e.g., 28–32 HRC for AISI 4140).

Packaging Customization:

Bundling by weight limits, rust-inhibiting VCI film wrapping, and heavy-duty wooden crating for sea freight protection.

Quality Control & Inspection

Material compliance is verified across three distinct production checkpoints:

Raw Material Verification: Spectrometric chemical analysis performed on incoming steel billets to verify alloy composition against ASTM/EN specifications prior to rolling.

In-Process Dimensional Audits: Laser micrometer monitoring during hot rolling and cold drawing to check corner radii, width, and thickness tolerances continuously.

Non-Destructive Testing (NDT): Automated offline eddy current crack detection and ultrasonic testing performed on alloy steel bars (AISI 4140/4340) to detect internal laminations and surface seams.

Mechanical Testing: Tensile testing, yield strength verification, and Brinell/Rockwell hardness testing executed on test coupons taken from each heat lot.

Packaging & Shipping

Bundle Configuration:

Steel bars are bundled in hexagonal or square shapes weighing between 1,000 kg and 3,000 kg, secured with high-tensile steel strapping at intervals ≤ 1.2 meters.

Moisture Protection:

Anti-corrosion oil applied to bare steel surfaces, enclosed in woven polyethylene wrapping or VCI paper for ocean transport.

Container Loading:

Heavy-duty dunnage, wooden blocking, and edge protectors utilized inside 20ft / 40ft dry containers or open-top containers to prevent shifting and cargo damage during transit.

FAQ & Request a Quote

Q: What is the minimum order quantity (MOQ) for custom steel grades or non-standard sizes?

A: MOQ is typically 3 metric tons per size and grade for production runs. Stock items are available for partial-bundle shipments subject to inventory verification.

Q: Can you provide EN 10204 3.1 test reports prior to shipment?

A: Yes. Mill test certificates detailing actual chemical composition, heat number, and mechanical test results are transmitted via email upon order dispatch.

Q: What is the difference between hot-rolled and cold-drawn square bars in terms of tolerance?

A: Hot-rolled square bars have standard commercial tolerances suitable for general structural work. Cold-drawn square bars feature tighter dimensional control, smoother surface finishes (down to 1.6 μm), and higher yield strength due to strain hardening.

Q: Do you offer cut-to-length services for containerized shipping?

A: Yes. Bars can be precision-cut to fit 20 ft containers (maximum length 5,800 mm) or 40 ft containers (maximum length 11,800 mm) to minimize international freight costs.

Q: What packaging measures are used to prevent rust during ocean transit?

A: All bars receive a coat of rust-preventive oil and are wrapped in moisture-resistant VCI paper or heavy woven plastic sheets, with wooden spacers separating bundles for air circulation.

Q: How do you handle surface defects or straightness non-conformance?

A: Any material failing agreed tolerances or exhibiting surface cracking verified via our internal QA records is replaced or credited under our commercial warranty terms.

Request a Quote

To receive a formal quotation, please provide the following parameters:
Steel Grade: (E.g., AISI 1045, AISI 4140)
Dimensions: Width × Thickness × Length
Condition: Hot-rolled or Cold-drawn
Quantity: Metric tons or total pieces
Destination Port: Port name for CIF/FOB calculation

As one of the most professional square steel bar manufacturers and suppliers in China, we're featured by quality products and low price. Please rest assured to buy high-grade square steel bar in stock here from our factory.