Square and Rectangle ERW Welded Steel Pipes Q215 Q235 with Galvanized Oiled and Black Surface

1．Product Overview

Square and rectangle welded steel pipes are used for steel structures, industrial fabrication, furniture manufacturing, agricultural equipment, storage systems, handrails, support frames, and general construction applications.

The pipes are produced by ERW welding technology and can be supplied with galvanized, oiled, or black surface finish. Q215 and Q235 grades are commonly selected for structural fabrication and welded assemblies, while Q195, SPHC, SPCC, 08Yu, and 08Al can be used for forming and general fabrication requirements.

2．Technical Solution

The pipe is manufactured by forming steel strip into square or rectangle profile and welding it continuously through the ERW process.

Galvanized surface treatment improves corrosion resistance for outdoor and humid environments. Oiled surface provides temporary rust protection during transportation and storage. Black welded pipe is suitable for welding, painting, machining, and secondary fabrication.

Square and rectangle profiles provide flat connection surfaces, making them suitable for frames, racks, support structures, and welded fabrication projects.

3．Specifications

4．Application

This product is suitable for construction steel structures, supports, handrails, machinery frames, welded assemblies, table frames, chair frames, shelving systems, greenhouse structures, agricultural support frames, rack systems, storage structures, and general steel framework.

Square welded pipes are commonly used for columns, support frames, and structural fabrication.

Rectangle welded pipes are suitable for frames, braces, shelves, machinery structures, and load-bearing applications where directional strength is required.

5．Processing

The welded steel pipes support cutting, welding, punching, bending, drilling, galvanizing, painting, polishing, bundling, and general fabrication.

Customized pipe length, surface finish, and packing method can be supplied according to project requirements.

6．Advantages

• ERW welded structure supports stable weld seam quality and dimensional consistency.
• Galvanized, oiled, and black surface finishes meet different corrosion protection, storage, and fabrication needs.
• Square and rectangle profiles provide flat surfaces for welding, bolting, and frame assembly.
• The available size range supports light-duty fabrication and structural applications.
• Q215 and Q235 grades are suitable for common structural and welded fabrication use.
• Standard export packing supports container shipment and export projects.

7．How to Choose

• Choose galvanized square or rectangle pipe for outdoor structural use and humid environments.
• Choose black welded pipe for indoor fabrication, welding, painting, and machining.
• Choose oiled welded pipe when temporary anti-rust protection is required during storage or shipment.
• Choose Q235 steel pipe for general structural fabrication.
• Choose Q195 or Q215 steel pipe for light forming and general fabrication applications.
• Choose large-size square or rectangle pipe for heavier support structures.
• Confirm pipe shape, size, wall thickness, steel grade, surface finish, length, and packing method before production.

8．FAQ

Q1．What pipe shapes are available

Square and rectangle welded steel pipes are available.

Q2．What surface finishes can be supplied

Galvanized, oiled, and black surface finishes are available.

Q3．What steel grades are available

Q195, Q215, Q235, SPHC, SPCC, 08Yu, and 08Al are available.

Q4．Can customized length be supplied

Yes. Customized pipe length is available according to customer requirements.

Q5．What industries commonly use these pipes

Construction, furniture, industrial fabrication, agriculture, warehousing, and general engineering industries commonly use these pipes.