Square Steel Tube (SHS)

1. Square Tube (SHS Steel) Supplier

Square tubes are one of the most commonly used structural sections in steel fabrication, widely used for columns, frames, and load-bearing structures.

We supply square hollow sections (SHS) in a wide range of sizes, wall thicknesses, and international standards including ASTM A500 and EN 10219, suitable for both standard projects and custom fabrication.

2. What Is Square Tube?

Square tube, also known as Square Hollow Section (SHS), is a welded hollow structural steel profile with four equal sides. It is widely used in structural, construction, industrial, and mechanical applications where high strength and dimensional stability are required.

Its symmetrical cross-section provides uniform strength in both directions, making square tubes suitable for structural columns, frames, equipment supports, and other load-bearing applications.

Compared with rectangular tubes, square sections are typically selected when balanced strength is required, while rectangular sections are more commonly used for directional bending.

For a detailed comparison, see Square Tube vs Rectangular Tube (SHS vs RHS): Which Is Better?       

3. Square Tube Specifications & Standards

Eastern Steel manufactures ERW square tubes (SHS) for structural, construction and industrial applications worldwide.

Item	Specification
Product Type	Square Hollow Section (SHS)
Manufacturing Process	ERW (Electric Resistance Welded)
Shape	Square
Width & Height	20–400 mm
Wall Thickness	2.0–20 mm
Standard Length	6 m / 12 m / Custom
Surface Finish	Black / Hot-Dip Galvanized / Pre-Galvanized
Standards	ASTM A500, ASTM A36, EN 10210, EN 10219, JIS G3466, GB/T 6728
Steel Grades	ASTM A500 Gr.B, ASTM A36, S235JRH, S275J0H, S355J2H, Q235B, Q355B

4. Available Sizes

Square steel tubes are available in standard sizes from 20 × 20 mm to 400 × 400 mm for structural, fabrication, and engineering applications. Standard lengths include 6 m and 12 m, while custom lengths are available upon request.

For complete dimensions, wall thicknesses, and theoretical weights, please refer to:

Square Tube Sizes Chart

Square Tube Weight Chart

5. Available Steel Grades

Different projects require different mechanical properties and structural performance. Eastern Steel supplies square steel tubes in multiple international steel grades to meet regional standards and engineering requirements.

Steel Grade	Common Standard	Typical Applications
ASTM A500 Grade B	ASTM A500	Structural steelwork, industrial buildings, equipment frames
ASTM A36	ASTM	General fabrication and welded structures
ASTM A513	ASTM	Mechanical tubing and precision fabrication
S235JRH	EN 10219 / EN 10210	General structural fabrication
S275J0H	EN 10219	Medium-strength structural applications
S355J2H	EN 10219 / EN 10210	Heavy structures, bridges, industrial buildings
Q235B	GB/T 6728	General construction and fabrication
Q355B	GB/T 6728	Structural engineering and heavy fabrication

The final steel grade is typically selected according to structural design requirements, applicable standards, fabrication methods, and project specifications.

6. Common Applications

Square tubes are widely used as structural steel tubes in buildings, industrial plants, bridges and engineering projects.Due to their symmetrical shape and good load distribution, SHS steel is suitable for both vertical and multi-directional load conditions.

Typical applications include:

① Structural columns and frames in steel buildings

② Load-bearing supports in construction projects

③ Machinery and equipment frames requiring rigidity and stability

④ General fabrication and engineering structures

Square tubes are commonly selected for columns and structural frames, while rectangular tubes are generally preferred where greater directional bending strength is required.

7. Ordering Information

In actual projects, buyers usually focus on availability, delivery time, and surface protection rather than just specifications.

Availability: 

Small and medium sizes (≤100 mm) are commonly available from stock or with short lead times. Larger sections (≥150 mm) are typically produced based on order quantity and project requirements.

Lead Time:

- Standard sizes: usually 7–15 days  

- Large or heavy sections: 15–30 days depending on production schedule  

Surface Treatment Options:

To improve corrosion resistance, square tubes are commonly supplied with different surface finishes:

- Black steel (mill finish) for general use  

- Painted surface for basic protection during transport and storage  

- Hot-dip galvanized for outdoor and corrosive environments  

Hot-dip galvanizing forms a protective zinc layer on the surface, which significantly extends service life in outdoor applications.

Factors Affecting Price:

Square tube pricing is mainly influenced by:

- Size and wall thickness  

- Steel grade (e.g., S235, S355, ASTM A500)  

- Surface treatment (black, painted, galvanized)  

- Order quantity  

MOQ: 

Minimum order quantity depends on size and specification. Standard sizes are more flexible, while non-standard or large sizes usually require higher quantities.

If you are working on a specific project, it is recommended to confirm size, grade, and surface requirements together to ensure accurate quotation and production planning.

8. FAQs

Q1. What is square tube (SHS steel) used for?

Square tubes are used for structural columns, frames, load-bearing structures, equipment supports, and general fabrication where balanced strength is required in both directions.

Q2. What are the standard square tube sizes?

Eastern Steel supplies standard square tubes from 20 × 20 mm to 400 × 400 mm with wall thicknesses ranging from 2.0 mm to 20 mm. Custom sizes and lengths are also available.

Q3. What steel grades are available for square tubes?

Available grades include ASTM A500 Grade B, ASTM A36, S235JRH, S275J0H, S355J2H, Q235B, and Q355B. Other grades are available upon request.

Q4. Can square tubes be galvanized?

Yes. Square tubes are available in black, pre-galvanized, and hot-dip galvanized finishes to suit different service environments.

Q5. Can square tubes be customized?

Yes. We can customize dimensions, wall thickness, length, steel grade, and surface finish according to your project requirements.

Q6. What is the difference between SHS and RHS?

SHS has four equal sides and provides balanced strengh in both directions, making it ideal for columns and structural frames. RHS has unequal sides and is generally preferred where higher bending strength is required in one direction.