home Company Profile Construction results Business content Employment information Inquiries Nagakuni Iron Works Co., Ltd. is a factory certified by the Minister of Land, Infrastructure, Transport and Tourism. What is M grade? Evaluation of steel frame manufacturing plants is carried out by classifying building structures with welding into five grades according to the building scale, steel materials used, etc. There are five grades, J, R, M, H, and S. We are an M grade certified factory, but J grade and R grade have restrictions on the height of the building scale, while M grade and later have no height restrictions. In order to obtain grade certification, it is necessary not only to look at the manufacturing capacity but also to have a quality control system and an inspection system in place. TOPICS Homepage opened May 18, 2017 home Company Profile Construction results Business content Employment information Inquiries 38 Teranokoshi, Josuiji, Ichinomiya City, Aichi Prefecture 491-0004 TEL.0586-76-4551 Homepage opened © 2020 Nagakuni Iron Works. All Rights Reserved.