Rongheng Intelligent Manufacturing supplies ERW Square Steel Tubes manufactured from quality hot-rolled steel strip through high-frequency electric resistance welding, forming, sizing, straightening and precision cutting.
Designed for structural frameworks, equipment manufacturing, infrastructure, machinery, furniture and general fabrication, our ERW square tubes combine consistent dimensions, reliable weld quality, efficient production and competitive bulk pricing.
Standard and customized sizes are available for engineering projects, long-term procurement and OEM requirements.
For steel pipe buyers, product consistency is often as important as the nominal specification. Variations in wall thickness, straightness, corner geometry or weld quality can create problems during fabrication and installation.
Rongheng's ERW Square Steel Tube is produced through a controlled high-frequency welding and sizing process to maintain consistent section dimensions and stable mechanical performance. Automated forming, sizing and cutting help reduce dimensional variation and provide square tubes that are easier to fabricate, weld and assemble.
For projects requiring corrosion protection, hot-dip galvanized square steel pipe can also be supplied.
It is a hollow square structural section manufactured by electric resistance welding.
During production, steel strip is progressively formed into a square or rectangular section. High-frequency electrical resistance heating is used to heat the strip edges, followed by pressure welding to create a longitudinal seam. The tube is then sized, straightened and cut to the specified length.
Compared with seamless square tubes, the pipe offers an efficient manufacturing route for a wide range of structural and fabrication applications. It is particularly suitable for projects requiring large quantities of consistent square tubing at a controlled cost.
The production process generally includes:
Hot-rolled steel strip → Roll forming → High-frequency ERW welding → Sizing → Straightening → Cutting → Inspection → Bundling and shipment
High-frequency electric resistance welding joins the longitudinal edges without conventional filler metal. Controlled welding parameters help produce a consistent and continuous weld seam.
The weld area is monitored during production to reduce the risk of common defects such as incomplete welding, cracks and excessive weld irregularities.
For applications requiring additional verification, inspection and testing can be arranged according to the agreed product specification.
Automated forming and sizing equipment controls the outside dimensions, corner geometry and straightness of the tube.
Consistent dimensions are particularly important for:
● Steel structure fabrication
● Equipment frames
● Mechanical assemblies
● Guardrails and barriers
● Furniture frames
● Standardized fabrication
More consistent tubing can reduce the amount of adjustment required during cutting, drilling, welding and assembly.
ERW technology is well suited to continuous production and large-volume steel tube orders.
Rongheng supports both project-based procurement and long-term supply programs, with production organized according to required dimensions, material grades, lengths and surface treatment.
For large engineering projects, stable production capacity helps reduce supply interruptions and maintain consistent specifications across different batches.
Standard sizes are available, while customized dimensions can be produced according to project requirements.
Depending on the order, available processing options may include:
● Fixed-length cutting
● Precision cutting
● Deburring
● End chamfering
● Punching and drilling
● Bending
● Painting
● Hot-dip galvanizing
● Corrosion-protection treatment
Customers can provide drawings, specifications or project requirements for technical evaluation before production.
|
Item |
Specification |
|
Product Name |
ERW Square Steel Tube / High-Frequency Welded Square Steel Tube |
|
Manufacturing Process |
High-Frequency Electric Resistance Welding |
|
Available Materials |
Q195–Q235, Q235B, Q355A, Q355B, Q355C |
|
Square Size Range |
20 × 20 mm – 500 × 500 mm |
|
Wall Thickness |
1.0–11.5 mm |
|
Standard Lengths |
6 m, 9 m, 12 m |
|
Customized Length |
4–12 m or according to project requirements |
|
Surface Options |
Black, hot-dip galvanized and other customized treatments |
|
Applicable Standards |
GB/T 700, GB/T 13793, GB/T 3091 |
|
Weld Inspection |
Eddy Current Testing |
|
Additional Testing |
Hydraulic/Air Tightness Testing, Mechanical Property Testing |
|
Dimensional Inspection |
Full dimensional inspection according to agreed requirements |
Note: Material grades, dimensions, tolerances, testing requirements and surface treatment can be confirmed according to the customer's drawings, applicable standards and project specifications.
Rongheng supplies ERW square steel tubes in commonly used carbon structural steel grades, including:
Suitable for general structural fabrication, frames, supports and applications where standard carbon steel performance is sufficient.
A widely used structural steel grade for construction, fabrication and general engineering applications.
Q355A, Q355B and Q355C are available for applications requiring higher strength than standard Q235 structural steel.
The final steel grade should be selected according to the structural calculation, applicable standard and project requirements.
The appropriate surface treatment depends largely on the operating environment.
|
Application Condition |
Recommended Product |
|
Indoor structural frames |
Black ERW Square Steel Tube |
|
Dry indoor equipment frames |
Black ERW Square Steel Tube |
|
Concealed structural components |
Black ERW Square Steel Tube |
|
Outdoor structures |
Hot-Dip Galvanized Square Steel Pipe |
|
Road barriers and guardrails |
Hot-Dip Galvanized Square Steel Pipe |
|
Outdoor supports and brackets |
Hot-Dip Galvanized Square Steel Pipe |
|
Humid or corrosive environments |
Galvanized or specified corrosion-protection treatment |
Black square steel pipe is generally more economical for indoor or protected applications and can be painted or otherwise treated after fabrication.
For long-term outdoor exposure, hot-dip galvanized square steel pipe provides additional corrosion protection and is generally a better choice where the steel will be exposed to rain and moisture.
Rongheng ERW square steel tubes are used across construction, manufacturing, infrastructure and general fabrication.
Square tubes can be used for structural frames, secondary supports, roof structures, columns, beams and other fabricated steel components.
The consistent square section makes ERW tubing suitable for equipment frames, conveyor structures, machine supports, agricultural equipment and industrial fabrication.
Applications include guardrails, barriers, streetlight bases, traffic infrastructure supports, fencing structures and other outdoor fabricated components.
For outdoor applications, hot-dip galvanized square steel pipe can be selected for improved corrosion protection.
Square steel tubing is widely used for furniture frames, partitions, display structures, architectural frames and decorative metalwork where a clean, regular section is required.
Customized square tubing can be processed through cutting, drilling, bending and welding for vehicle components, equipment structures and other fabricated metal products.
Rongheng Intelligent Manufacturing operates within the steel manufacturing cluster of Daqiuzhuang, Tianjin, supported by established steel processing, raw material and logistics resources.
For ERW Square Steel Tube, quality control can cover the key stages from incoming raw material to finished-product inspection.
Steel strip is checked against the agreed material grade and purchasing specification before entering production.
The forming process and high-frequency welding parameters are controlled to maintain consistent tube geometry and weld quality.
After welding, the tube passes through sizing and straightening processes to control section dimensions and straightness.
Finished tubes can be inspected for:
● Outside dimensions
● Wall thickness
● Length
● Straightness
● Surface condition
● Weld quality
● Mechanical properties
Eddy current testing and other agreed inspection methods can be arranged according to product requirements.
Rongheng can manufacture steel pipe products according to applicable international, regional and customer-specific requirements.
Relevant standards for the product range include:
● GB/T 700 — Carbon structural steels
● GB/T 13793 — Electric resistance welded steel pipes
● GB/T 3091 — Welded steel pipes for low-pressure fluid service
For international projects, customers can also arrange third-party inspection and pre-shipment verification through recognized inspection organizations such as SGS, Bureau Veritas or TÜV, subject to project requirements.
Inspection documentation can be coordinated according to the purchase order and agreed quality requirements.
Not every project can use standard stock dimensions. Rongheng supports customized production for engineering and fabrication requirements.
Customization may include:
● Non-standard square dimensions
● Customized wall thickness
● Fixed cutting lengths
● Special length requirements
● Material grade selection
● Hot-dip galvanizing
● Painting and corrosion protection
● Drilling and punching
● Bending
● End processing
● Customized packaging
For non-standard projects, customers can send us the required dimensions, wall thickness, steel grade, length, quantity, surface treatment and applicable standard. Technical and production requirements can then be evaluated before quotation.
Rongheng Intelligent Manufacturing is positioned to support both regular procurement and large-scale project orders.
Backed by the group's established steel manufacturing resources and annual steel production and sales volume of more than 1.3 million tons, Rongheng can coordinate raw material sourcing, production, inspection and export logistics for large-volume requirements.
Typical supply requirements include:
● Bulk orders for construction projects
● Long-term supply contracts
● Steel structure projects
● Machinery manufacturing
● Infrastructure projects
● OEM and ODM requirements
● Customized non-standard steel tubes
Minimum Order Quantity: 1 × 20-foot standard container, approximately 20–25 tons.
Standard Lead Time: 15–25 days, subject to product specifications, order quantity and customization requirements.
Choosing the correct square tube should be based on more than outside dimensions.
The required width and height depend on the structural design, available installation space and load requirements.
Wall thickness should be determined according to the expected load, span, connection method, fabrication process and applicable structural requirements.
If you are unsure about the appropriate wall thickness, provide the application, span, expected load and installation conditions. Our sales and technical team can help identify suitable specifications for quotation.
Q235 grades are widely used for general structural applications, while Q355 grades can be considered when higher strength is required.
The final selection should follow the project's engineering calculations and applicable standards.
For indoor and protected applications, black square steel pipe is often sufficient.
For outdoor or humid environments, hot-dip galvanized square steel pipe is generally recommended for improved corrosion resistance.
Our current standard product range covers square sections from 20 × 20 mm to 500 × 500 mm, with wall thicknesses from 1.0 to 11.5 mm. Standard lengths include 6 m, 9 m and 12 m. Customized dimensions and lengths can be evaluated according to project requirements.
Yes. Rongheng supports customized dimensions, wall thicknesses, fixed lengths and additional processing. For non-standard requirements, please provide the required section size, wall thickness, steel grade, length, quantity and applicable standard.
ERW square pipe is manufactured by forming steel strip and welding the longitudinal seam using electric resistance welding. Seamless tube is manufactured without a longitudinal welded seam.
ERW square tubing is widely used for structural and fabrication applications where consistent dimensions and cost-efficient bulk production are important. Seamless products may be preferred for specific applications requiring seamless construction or special pressure-related performance.
Yes, but surface protection should be considered. For long-term outdoor exposure, hot-dip galvanized square steel pipe is generally more suitable than untreated black steel pipe because the zinc coating provides additional corrosion protection.
Yes. Rongheng supplies both black ERW Square Steel Tube and hot-dip galvanized square steel pipe. Galvanizing specifications can be discussed according to the required coating weight, project environment and applicable standard.
Yes. Depending on the order, we can provide fixed-length cutting, deburring, chamfering, drilling, punching, bending, painting and other processing services. Processing requirements should be confirmed before production.
Wall thickness depends on the intended application, load, span, connection method and applicable engineering requirements. If you provide the application and basic load information, we can help identify suitable product specifications for further engineering verification.
Quality control can include dimensional inspection, wall-thickness measurement, weld inspection, eddy current testing, mechanical property testing and other agreed inspection procedures. Third-party inspection by organizations such as SGS, BV or TÜV can also be arranged for international orders when required.
Our standard MOQ is one 20-foot container, approximately 20–25 tons. The standard lead time is approximately 15–25 days, depending on specifications, order quantity, surface treatment and customization requirements.
Yes. Rongheng supports bulk steel pipe procurement for construction, infrastructure, machinery and industrial projects. Our supply system can coordinate production, quality inspection, packaging and export logistics for large-volume orders.
Rongheng Intelligent Manufacturing combines steel manufacturing resources in Tianjin, large-volume supply capability and international export experience to support customers from specification confirmation through production and shipment.
● Factory-backed supply system with established steel manufacturing resources
● Annual steel production and sales exceeding 1.3 million tons
● ERW square and rectangular steel tube production
● Wide range of dimensions and steel grades
● Black and hot-dip galvanized options
● Non-standard size and processing customization
● Quality inspection and third-party inspection support
● Bulk supply for engineering and long-term procurement
● International export experience across Asia, the Middle East, Africa and South America
● 15–25 day standard lead time, subject to order requirements
For a quotation, send us your square pipe size, wall thickness, steel grade, length, quantity, surface treatment and destination. We can evaluate the specification and provide a suitable supply solution.
Address
Secondary Arterial Road No. 2-1, Expansion Area of Daqiuzhuang Industrial Zone, Jinghai District, Tianjin, China
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