Company introduction



Address 165 Kubo-cho, Himeji City, Hyogo Prefecture, Japan 670-0916
Tel. 079-281-9001
FAX 079-285-0612
Employees 200 persons
Capital ¥5.75 million
Established May, 1985
President Keigo Miki


Steel Structure Group: gas cutting products (cut steel sheet products), built-up steel section (H & T − beams) manufacturing, and the primary and secondary processing and sale of steel


Applying all the technologies refined over the years…
Independently developed Japan’s largest automated welding equipment!

Automated gull-wing high-speed welding equipment Tamano factory with its private quay Seasoned engineers’ skills meet cutting edge technology

“Everything is for the customers’ satisfaction! Our products act as our sales representatives while the factories serve as our showrooms!” Under this motto, Katsura Steel continues to strive for producing quality products in the most efficient and safe manner. We manufacture and process large-scale custom order “built-up H-beam” steel structures often used for columns and beams for architectural structures and civil engineering works. With a domestic market share of 35%, we are a leading manufacturer in the field. Meticulously responding to customer requests regarding load capacity, thickness and shape, we carry out our uninterrupted line of production from the cutting and welding of steel to its processing and delivery. Combining this with the unique production management system we developed, we utilize our strength of being a one-stop service platform for customers, and continue to grow even more powerfully. Katsura Steel independently developed numerous types of machinery equipment and introduced them into welding processes which greatly influence the quality of finished products. The high-speed, high-quality submerged arc welding (SAW) process is Katsura Steel’s largest technological forte as it incorporates the nation’s largest-scale “gull-wing” type and “buffalo” type high-speed automated welding equipment as the process’s key components. Profiling sensors travel flexibly even on subtle contortions and warpings of the steel to achieve metal welding precisely as designed. We are currently working towards both increasing our fabrication efficiency and stabilizing our product quality. On the other hand of increasing machinery and automation adaptations, the skills of seasoned workers are also essential in order to bring out the best use of cutting-edge equipment in order to produce higher quality. By fastidiously improving techniques and accumulating expertise, Katsura Steel is determined to constantly upgrade its product appeal which is conducive to boosting customer satisfaction. *SAW stands for submerged arc welding and is a method to weld metals via electric discharge by applying a fusing agent onto the welding seams.

【Development background】

The passion to meet the needs of customers ever faster, ever more efficiently, and with ever better quality products, and the company target to establish a system for ensuring production volume while controlling work hours in consideration of succeeding generations: these two key values are the engines of the company’s efforts to pursuing more efficient and automated production processes. When Katsura Steel needs equipment to establish a required processing system, but none is available in the market, we develop it independently. This aggressive technological development has occasionally ended in vain by producing unusable machines; however, this determination to embody the company ideal has not changed since the establishment of the company.


Katsura Steel’s most distinctive characteristic and its biggest strength is its one-stop service platform built by independently developing an integrated enterprise system which enables us to swiftly fulfill versatile customer expectations, from procuring materials to managing yields. A part of the platform is the introduction of the bar code system to keep track of process progress and inventory which can get a grasp of manufacturing processes and material and inventory management in real-time. Katsura Steel’s high-quality products in minimum delivery time at low costs keep the company able to constantly contribute to projects requiring large structural materials.

【Future developments】

Construction of the Tokyo Olympics-related facilities, urban re-development projects, seismic retrofitting for buildings, renovations of antiquated infrastructure, and the development of the Linear Chuo Shinkansen, to name just a few, exemplify the increasingly high-demand prospects of the construction business industry. As we are making plans based on a hard look at such future prospects, we imported Japan’s first Italian-made processing equipment model and also established a new factory. We are working even harder to transform the construction business industry into a more worker-friendly and fulfilling industry by enriching the working environment and nurturing human resources with the aim of pursuing even more efficiency and automation of manufacturing equipment in the future.


From educational programs to welding skills competitions
Monodzukuri Dojo (manufacturing hall) to foster human resources through versatile curricula

We opened the Monodzukuri Dojo (manufacturing hall) at Katsura Steel as a pivotal facility for manufacturing education. The key skill for our operators is ironworking. In order to elevate their welding skills, an annual Welding Skills Competition is held every fall and participated in by all company employees. Disclosing the in-house ranking of the competition urges staff to compete against each other and through this, we mutually elevate our skills and grow together. The hall also doubles as a JIS Certification Test venue for workers’ evaluation tests. Under the mutual slogan of “All we do is for the customers’ satisfaction,” we pursue the ideal form of manufacturing by means of various curricula.

A new Bizen factory opened in March, 2017
We aim to boost the quality of ultra-thick steel structures including civil engineering and bridges

Immediately adjacent to the Okayama No. 2 factory in Bizen city, Okayama Prefecture, there are two new factory complexes. At these complexes with a total ground area of approximately 15,000 square meters and total floor area of 2,800 square meters, machinery that can weld thicker steel materials than ever before is installed.
Normally, steel materials used for constructing buildings are 40 mm thick, however, at these new complexes, steel materials of up to 100 mm can be processed.
Hand in hand with the surge in demand for constructing the Linear Chuo Shinkansen and thermal power plants, we aim to expand our manufacturing capacity of thicker steel materials.


1985 Established as Katsura Steel Co., Ltd.
1997 Acquired the steel structure manufacturing factory grade M certification.
2000 Opened the Okayama No. 2 factory.
2003 Acquired the ISO9001 certification
2005 Acquired the steel structure manufacturing factory grade H certification.
Opened the Okayama No. 3 factory.
2009 Opened the Monodzukuri Dojo (manufacturing hall).
2010 Opened the Okayama No.5 factory.
2012 Acquired AAA certification for built-up H-beams steel manufacturing.
2013 Opened the Tamano factory.
2015 Opened the Himeji factory.
2016 Completed the frame construction for the quay of the Tamano factory