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High Strength ASTM A500 Q355B Steel Square Hollow Section Tube for Steel Structure Building Projects | China Manufacturer
| Welded Steel Square Tube (SHS) - Core Specifications | |
| Item | Specification |
| Product Name | Welded Steel Square Tube (SHS) |
| Material Grade | ASTM A500 Grade B, ASTM A500 Grade C, Q355B |
| Standard | ASTM A500, GB/T 6728, EN10219 (Optional) |
| Outer Size | 20×20mm – 500×500mm |
| Wall Thickness | 0.8mm – 20mm |
| Length | 5.8m, 6m, 12m or Customized |
| Manufacturing Process | Cold Formed, Hot Rolled, ERW Welded |
| Surface Finish | Black, Oiled, Painted, Hot-Dip Galvanized |
| Zinc Coating | 40–600g/m² (for galvanized tubes) |
| Certification | ISO 9001, Mill Test Certificate (MTC) |
| Trade Terms | FOB, CFR, CIF, EXW |
| ASTM A500 Grade B / Grade C & Q355B Square Steel Pipe – Chemical Composition by Grade | |||
| Element | ASTM A500 Grade B | ASTM A500 Grade C | Q355B |
| Carbon (C) | Max 0.26 | Max 0.23 | Max 0.24 |
| Manganese (Mn) | Max 1.35 | Max 1.35 | Max 1.60 |
| Phosphorus (P) | Max 0.035 | Max 0.035 | Max 0.035 |
| Sulfur (S) | Max 0.035 | Max 0.035 | Max 0.035 |
| Silicon (Si) | — | — | Max 0.55 |
| Copper (Cu) | Min 0.20* | Min 0.20* | — |
| Nickel (Ni) | Optional | Optional | Optional |
| Chromium (Cr) | Optional | Optional | Optional |
| Vanadium (V) | — | — | Max 0.15 |
| Niobium (Nb) | — | — | Max 0.07 |
| Titanium (Ti) | — | — | Max 0.20 |
| ASTM A500 Grade B / Grade C & Q355B Square Steel Pipe – Mechanical Properties | ||
| Grade | Yield Strength | Tensile Strength |
| ASTM A500 Grade B | ≥ 315 MPa | ≥ 400 MPa |
| ASTM A500 Grade C | ≥ 345 MPa | ≥ 427 MPa |
| Q355B | ≥ 355 MPa | 470–630 MPa |
Core Advantages of Welded Square Hollow Tubes
Superior Structural Performance
Fabricated from ASTM A500 Grade B/C and Q355B steel grades, these square tubes feature outstanding yield strength and robust load-bearing capability, perfectly suited for heavy-duty structural engineering applications.
Easy Fabrication & Welding Performance
Controlled low carbon composition ensures reliable weldability and convenient secondary machining, effectively shortening on-site construction cycles and lowering overall project expenditure.
Tight Dimensional Tolerance
Rigorous full-process quality inspection ensures consistent outer dimension, straightness and even wall thickness across each tube piece.
Flexible Anti-Corrosion Solutions
A full range of surface treatment options are available, including black finish, rust-proof oil coating, painted coating and hot-dip galvanization, adapting to diverse service environments.
Optimized Cost Budget
ERW welded square structural pipes balance stable mechanical performance and favorable unit pricing, bringing distinct cost advantages to bulk procurement projects.
ASTM steel pipe refers to carbon steel pipe used in oil and gas transmission systems. It is also used to transport other fluids such as steam, water, and mud.
The ASTM STEEL PIPE specification covers both welded and seamless fabrication types.
Welded Types: ERW Pipe
Welding Compliance and Inspection for ASTM A53 Square Steel Pipe
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Welding Method: ERW (Electric Resistance Welding)
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Standards Compliance: Fully conforms to ASTM A53 welding process requirements
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Weld Quality: 100% of welds pass non-destructive testing (NDT)
Note: ERW welding ensures strong, uniform seams, meeting structural performance and safety standards for columns, trusses, and other load-bearing applications.
| Application Scenario | Specification (Size × Thickness) |
| Construction & Steel Structure | 50 × 50 × 3.0 mm |
| 75 × 75 × 3.0 mm | |
| 100 × 100 × 4.0 mm | |
| 150 × 150 × 6.0 mm | |
| 200 × 200 × 8.0 mm | |
| Warehouse & Workshop Buildings | 100 × 100 × 4.0–6.0 mm |
| 150 × 150 × 6.0–10.0 mm | |
| 200 × 200 × 8.0–12.0 mm | |
| Infrastructure & Heavy Structures | 250 × 250 × 10.0 mm |
| 300 × 300 × 12.0 mm | |
| 400 × 400 × 16.0 mm | |
| 500 × 500 × 20.0 mm | |
| Solar Mounting & Fence Systems | 40 × 40 × 2.0 mm |
| 50 × 50 × 2.5 mm | |
| 60 × 60 × 3.0 mm | |
| General Technical Parameters | |
| Available Standard | ASTM A500 Grade B, ASTM A500 Grade C, Q355B |
| Length | 5.8m, 6m, 11.8m, 12m or Customized |
| Surface Treatment | Black, Oiled, Painted, Hot-Dip Galvanized |
| Processing Service | Cutting, Drilling, Welding, Punching, Galvanizing, Custom Fabrication Available |
Contact Us
ASTM A500 Grade B/C & Q355B Square Steel Pipes
Available surface treatments:
Black Bare Steel
Anti-rust oiled finish
Red oxide primer coating
Hot-dip galvanized
Epoxy coating
Custom protective coatings
ASTM A500 Grade B Grade C & Q355B Weld Carbon Steel Square Tube Application
| Feature | Description |
| High Structural Strength | Made of ASTM A500 B/C & Q355B steel, great yield strength and load capacity for heavy structural use |
| Excellent Weldability | Low carbon material for easy welding and fabrication, saving time and costs |
| Precise Dimensions | Strict QC ensures accurate size, straightness and uniform wall thickness |
| Corrosion Protection | Available in black steel, anti-rust oil, paint and hot-dip galvanized finishes |
| Cost-Effective | Reliable performance with competitive pricing |
Royal Steel Group specializes in supplying structural steel pipes and hollow sectional profiles, boasting abundant overseas export experience.
Our sales network covers key global markets: North & South America, the Middle East, Southeast Asia, Africa and Europe.
We implement full-range strict quality inspection systems, cost-attractive quotations and tailor-made fabrication solutions.
Supported by stable international logistics arrangements, we assist worldwide buyers in executing infrastructure and building projects with higher efficiency and lower total investment.
All square steel tubes are firmly secured with steel strapping and waterproof packaging to avoid dampness and rust during transport. Custom export packaging is available for containers, bulk cargo and international project orders.
Q1: What steel grades are available?
Royal Steel Group supplies ASTM A500 Gr.B, ASTM A500 Gr.C, Q355B and other grades such as A53 square tube, Q235B, S275JR and S355J2H to meet various international project requirements.
Q2: Do you offer custom sizes and processing?
Yes. We provide sizes from 20×20mm to 500×500mm and offer custom services including cutting, drilling, punching, welding and beveling according to drawings.
Q3: How do you ensure product quality?
All products undergo strict quality inspections. MTC, ISO 9001 certificates and third-party inspections (SGS, BV, TUV) are available upon request.
Q4: What is your delivery time?
Standard products can be delivered within 7–15 days. Customized and bulk orders are scheduled with reliable production and export planning.
Q5: What surface treatments and packaging do you provide?
Available finishes include black steel, anti-rust oil, primer coating, hot-dip galvanizing and epoxy coating. Export packaging is designed to protect products during long-distance ocean transportation.
Contact Details
Address
Kangsheng development industry zone,
Wuqing district, Tianjin city, China.
Phone
Hours
Monday-Sunday: 24-hour Service
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