The Production speed of 30 meters per minute

Achieving international standards including ASTM, EN, DIN, JIS, …

Compliance with AWWA standard for producing water supply pipes

Obtaining the certificate of the Iranian Housing and Urban Development Research Center

The fully approved products by the well-known standards Thanks to the combination of high speed production and the outstanding quality of mill line machines

Hollow Structural Sections (HSS) stands for Hollow Structural Section that is a metal profile with a hollow cross section. Round, square and rectangular shapes of HSS profiles have many applications in various industries.

HSS profiles are being manufactured in 2 methods:

• Traditional production method (welding and cutting by manpower)

• Modern industrial production method (by fully automated and integrated machinery)

Traditional production has the following shortcomings:

• High percentage of workforce errors and thus less reliability

• Increased production time

• Increased required workforce

• Increased Production expense

• Considerable residual stress in welding zone

Modern industrial production method doesn't have the above shortcomings.

HSS has many various applications in different industries such as Construction, Oil and Gas, Municipal Engineering and many other industries.

Steel Advantages vs. Other Construction Materials

1. Steel construction is naturally faster than concrete or masonry

2. Due to its strength, structures built using steel are usually lighter than those made of other materials

3. Steel is fully recyclable

4. Due to its strength, construction using structural steel generally provides more room for open spaces, which is desirable in terms of architecture and aesthetics

5. Due to higher strength, steel is known to provide the best strength-to-weight ratio comparted to other construction material such as concrete or timber

HSS (produced by modern manufacturing) Advantages vs. Other Structural Steel Sections

1. Better strength-to-weight ratio

2. Stronger in torsion

3. Best for columns due to symmetry and material placement

4. Better welding quality

5. Useful in lightweight construction and better performance against earthquake forces

6. Useful in space structures

7. Better looking architectural exposure

8. Decreased construction costs and being more economical

9. Made to measure profile lengths

10. Much easier composite construction by using concrete-filled members

The following table indicates why using HSS, leads to time saving, higher quality and lower costs.

Comparing with Concrete Structures Comparing with Built-up Steel Structures

Decreasing the period of Concrete Structure Construction up to 70% Decreasing the period of Fabrication and Installation of Steel Frame up to 40% Time Advantages of HSS in compare with the other structural systems

Reduces the Dimension of Columns up to 30% Limited Reduction in Dimension and Thickness of Columns Weight

More economical due to remarkable decrease of construction time in Concrete Structures and Faster Return on Investment Leads to Cheaper Columns up to 20% and Cheaper Steel Frame up to 10% Cost

Much higher quality due to elimination of numerous Human mistakes and environmental Factors affecting on the construction quality

1. Much higher quality due to Controlled Electric Resistance Welding (ERW) Instead of Submerged Arc Welding (SAW)

2. Much higher quality due to Residual Stress Reduction (Welding Line Reduction) Quality

These comparisons are made in a 5-storey building with relative irregular plan and 2.5 up to 7.5-meter span (Including steel moment frame in X-direction and concentric brace (CBF) in Y-direction). Although the above-mentioned percentages may vary in different structures, it is expected that the advantages of HSS utilization are remarkable in all kinds of structures.

ATENA manufactures HSS using non-alloyed carbon steel which are either mild (ST-37), ST-44 or high strength (ST-52), in round, Square and Rectangular shape through cold forming and Electric Resistance Welding (ERW) method.

These sections are made of hot rolled coils with yield strength ranging from 240 to 360 mpa, and ultimate tensile strengths ranging from 370 to 520 mpa. This corresponds to an ultimate elongation of about 15-17 percent.

After cold-working process, yield strength and ultimate strength increases which is one of the advantages of the production method and arises from strain hardening in stress-strain curve.

Cold Formed ERW Structural and Mechanical Tubing of Non-Alloy Steels ASTM A500

ASTM A1085

EN 10219

DIN 59411

JIS G3466

Steel Water Pipes-6 inch (150 mm) and Larger AWWA-C200

As indicated before one of the most important applications of HSS is in the construction industry. Generally, using steel structure is more beneficial than other structures and construction materials such as concrete, and with no doubt HSS is one of the bests among them. Having two or more axes of symmetry and large radii of gyration, HSS profiles are the most suitable choices as columns or beam-columns of the main load resisting systems of structures.

The tubular form of HSS is inherently strong and efficient compared to other steel profiles, since its material is the farthest from the centroidal axes. Furthermore, all section parts are considered “stiffened” according to AISC standards. Hence, HSS has a better strength to weight ratio, even when compared to other structural sections. A lower weight naturally leads to easier construction, reduced earthquake-induced loads, reduced erection and transportation costs, and more economical design of other structural parts such as foundations. This also makes HSS suitable for extensions of existing buildings without overloading their foundations.

According to researches it is proven that concrete structures are the most earthquake prone. This arises from undeniable errors of workforces in built-up sections. Also the workshop errors in making steel structures are not negligible as there is high residual stress in the sections by this method resulting from several cutting and welding processes repeatedly which leads to structure vulnerability during earthquake.

Therefore, it is certainly essential to be more accurate in selecting resistant and reliable materials in many regions such as Turkey which are exposed to earthquake hazards. HSS produced by modern industrial method is the safest and the most credible construction material against this natural disaster.