Square Tube

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.

- Size range: 20 × 20 mm to 400 × 400 mm  

- Wall thickness: 2.0 mm to 20 mm  

- Standards: ASTM A500, ASTM A36, EN 10210, EN 10219  

Contact us for price, stock availability, and custom sizes.

2. What is Square Tube (SHS Steel)?

Square tube, also known as Square Hollow Section (SHS), is a structural steel profile with four equal sides.

Its symmetrical shape provides uniform strength along both axes, which makes it a practical choice for columns, frames, and structures where loads act from multiple directions.

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 Sizes

We supply square tubes in a wide range of sizes and wall thicknesses to meet different structural requirements.

Commonly ordered sizes include 40 × 40 × 2.5 mm, 50 × 50 × 3 mm, and 100 × 100 × 4 mm, while larger sections such as 200 × 200 mm are typically used in heavy structural applications.

Typical sizes include:

Square tubes are described by their height, width, and wall thickness.  For example, 100 × 100 × 10 SHS means 100 mm × 100 mm with a 10 mm wall thickness.

4. Standards and Materials

Our square tubes are produced according to international standards to meet different structural and engineering requirements.

Common materials include ASTM A500 Grade B, ASTM A513 (1020–1026), and ASTM A36.

European standards such as EN 10210 and EN 10219 are also available, with grades including S235, S275, and S355.

In practical applications:

ASTM A500 Grade B is widely used for general structural purposes

S355 (EN standards) is preferred when higher strength is required

ASTM A36 is typically used for basic fabrication and non-critical structures

Material selection is usually based on load requirements, fabrication method, and whether higher strength or weldability is prioritized.

5. Applications

Square tubes are commonly used in structural applications where uniform strength is required in both directions.

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 especially suitable for column-type structures, while they are less commonly used for primary bending beams compared to rectangular sections.

6. Supply & Purchasing 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.

Pricing Factors:

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.

7. FAQs

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

Square tubes are mainly used for structural applications such as columns, frames, and load-bearing structures where strength is required in multiple directions.

Q2. What sizes are available for square tubes?

We supply square tubes from 20 × 20 mm up to 400 × 400 mm, with wall thickness from 2.0 mm to 20 mm.

Custom sizes and lengths can be provided based on project requirements.

Q3. Can you customize square tubes?

Yes. We support custom sizes, wall thickness, and length according to your drawings or specifications.

Surface treatments such as galvanizing or coating are also available.