Hot finished
square hollow sections


Unique, economically designed steel pipe highly resistant to earthquakes.

Hot finished square hollow sections are Structural steel pipes highly resistant to earthquakes and with the inherent toughness of steel obtained by hot finished. Through technical collaboration with British Steel (the current Tata Steel) in the UK on hot finished and our proprietary technology, NSP developed a unique Hot finished square hollow section named “SUPER HOT COLUMN” and succeeded in putting it into mass production. SUPER HOT COLUMN in large sizes up to 800 mm x 800 mm in side length and 70 mm in thickness is certified according to EN10210. NSP also manufactures products conforming to ASTM A501/A501M. The quality of these products is highly thought of in the global market.

Manufacturing Process

Electric resistance
welded steel pipes

To the next process
Heating process

Automatic arc welded
steel pipes

To the next process
Heating process

Heating process


An ideal material with excellent mechanical properties and homogeneous hardness distribution.

Formed after being heated and soaked, SUPER HOT COLUMN is homogeneous both in hardness and in Crystal grain throughout its cross-section without work hardening, achieving equivalent or better material properties than SN grade products. The inherent toughness and high strength of steel and outstanding plastic deformation capacity make SUPER HOT COLUMN an ideal tough steel material for buildings. SUPER HOT COLUMN has high buckling strength and excellent weldability without residual stress. Cracks will not occur in the rounded corners of square steel pipes even when they are hot-dip galvanized. With SUPER HOT COLUMN, the inherent performance of steel is evinced even in the corners and weld seam sections.

Advantages of SUPER HOT COLUMN

SUPER HOT COLUMN can reduce the column weight and weld volume with its small cross section when used for medium- to high-rise buildings with spans over 10 meters. Furthermore, downsizing of the fireproof coating area and finishing area made possible by SUPER HOT COLUMN leads to architectural design advantages and overall cost reduction. In addition, SUPER HOT COLUMN, featuring constant design strength that does not decline even at a sheet thickness above 40 mm, offers significant cost reduction compared to welded box columns.

Highly regarded in Japan and abroad.

SUPER HOT COLUMN is highly regarded for its performance and superior resistance to earthquakes. It has been certified as a designated Structural steel pipe by the Ministry of Land, Infrastructure, Transport and Tourism of Japan and was acknowledged with the Director-General’s Award from the Science and Technology Agency of Japan. SUPER HOT COLUMN is in compliance with international standards, including the CE Mark, a European safety standard. The company owns patents in Europe and the United States as well as in Japan, and the product is highly regarded in global markets for its overall quality.