1. Standard compliant structural square hollow section: ASTM A500 & ASTM A36, meets GB/T 6728, EN 10210/10219, JIS G3466 global structural pipe standards
2. Full size range: Side dimension 10*10–1000*1000mm, wall thickness 0.8–30mm, strict tolerance ±0.5mm for side width, ±0.05mm for wall thickness
3. Mature high-frequency ERW welding production line, full non-destructive inspection after forming to eliminate welding defects
4. Multiple customizable surface treatments: Black bare, anti-rust oil, hot galvanizing, paint, powder coating, PVC coated finish
5. Complete material grade options: A36, A500 A/B/C, Q195/Q235/Q345, S235JR/S355JR, SS400, St37/St52
6. Flexible length customization: Fixed 5.8m/6m/12m or arbitrary cut length per client drawing requirements
7. Stable monthly output up to 10,000 tons, low MOQ of 25 tons, flexible payment: T/T, L/C; trade terms FOB/CFR/CIF
8. Standard bundled export packaging with steel strips and waterproof plastic bags, suitable for long-distance sea transportation

ASTM A500 Grade A36 carbon square steel pipe is cold-formed high-frequency welded structural hollow section, specially developed for building frames, machinery structures, furniture and fence projects. Adopting uncoiling, flattening, roll forming, high-frequency welding, deburring, cooling and online NDT integrated production process, every finished pipe passes dimensional and surface full inspection before warehousing.

We supply square & matching rectangular hollow sections with complete specifications. Multiple anti-corrosion surface treatments can be customized according to outdoor, marine and indoor service environments. All raw materials adopt qualified mild carbon steel coils with stable mechanical performance, excellent welding and cold forming performance, easy for cutting, punching, bending and secondary CNC machining. Widely exported to global construction, decoration and mechanical manufacturing industries.

方管生产工艺流程

• Universal low-carbon structural steel, minimum yield strength 250MPa, tensile strength 400–550MPa
• Excellent plasticity, weldability and cold bending performance, no brittle cracking during punching and forming
• Low impurity content of sulfur & phosphorus, stable mechanical properties for indoor & general outdoor structural frames
• Cost-effective general structural material for construction, furniture and equipment support

• Cold-formed welded structural tubing dedicated for load-bearing frames
• Grade A: Min tensile 310MPa, yield 269MPa, elongation ≥25% for light load structures
• Grade B: Min tensile 400MPa, yield 317MPa, elongation ≥23%, most widely used for building frames
• Grade C: Min tensile 427MPa, yield 345MPa, elongation ≥21%, for heavy load engineering
• Uniform wall thickness and stable section rigidity after cold forming

• S235JR / Q235: Yield ≥235MPa, economical grade for conventional structural projects
• Q345 / S355JR: High strength low alloy steel, yield ≥345MPa, suitable for heavy load, large-span construction frames

We supply matching square, rectangular, round shaped hollow sections and alloy pipes for all structural & pipeline projects:

1. Mild Carbon Structural Hollow Section: ASTM A36, A500 A/B/C, Q195/Q235/Q345, S235JR/S355JR, SS400, St37/St52
2. Conventional Round Carbon Pipe: ASTM A53, A106 Gr.B, API 5L line pipe
3. High Temperature Alloy Pipe: ASME SA335 P11/P22/P91, ASTM A519 mechanical alloy tube
4. Stainless Structural Tube: 304, 316L, 321 square & rectangular hollow sections
5. Special Corrosion Resistant Alloy: Alloy 28 seamless pipe, ASTM B167 nickel alloy tube

Side width tolerance ±0.5mm, wall thickness tolerance ±0.05mm, consistent section size for easy assembly and bolt connection.

Uniform welding seam without hidden crack defects, online non-destructive inspection ensures pipeline & structural safety.

Black bare, oiled, hot galvanized, powder coated finishes available to match indoor, outdoor, coastal different service environments.

Low-carbon formula supports cutting, drilling, punching, bending and all mainstream welding processes for on-site fabrication.

Monthly output reaches 10,000 tons, small batch order acceptable, stable delivery within 10–45 days after deposit.

Steel strip bundling + inner waterproof plastic bag, uniform batch marking to avoid rust and collision damage during long sea shipment.

• Building engineering: Workshop steel frames, column beams, roof trusses, bridge auxiliary supports
• Furniture & interior decoration: Metal furniture frames, exhibition stand, indoor partition frames
• Municipal facilities: Guardrail, fence, traffic sign support frame
• Mechanical manufacturing: Equipment base, conveying rack, mechanical protective frames
• Agricultural facilities: Greenhouse skeleton, breeding equipment support
• Logistics storage: Warehouse shelf, storage rack structural components

We provide integrated forging and precision machining services, and can produce finished components strictly according to customer drawings:

Turning, milling, planing, drilling, boring, grinding

Gear cutting, CNC precision machining

Sizing cutting, surface treatment and finishing

We have supplied a wide range of forged and machined parts including shafts, cylinders, hollow bars, pistons, tube sheets, rings and disc bearings to customers worldwide.

We have a professional QC inspection team and complete testing equipment to ensure stable and reliable product quality:

Ultrasonic testing (UT) for internal defects

Tensile and hardness testing for mechanical properties

High-precision dimensional measurement

Spectrometer for chemical composition verification

Metallographic microstructure inspection

Every batch of products undergoes strict inspection before delivery to meet the quality requirements of various engineering projects.

Inner packaging: waterproof polybag for moisture and dust protection

Outer packaging: reinforced wooden case / wooden pallet, suitable for long-distance international transportation

Custom packaging solutions available upon request

Normally 10 – 45 days after receipt of advance payment

Exact delivery time depends on order quantity, specification complexity and machining requirements