Galvanized (GI) Steel Coil Manufacturers in Korea

DONGKUKCM CO. LTD. was established in January 1977 by DongKuk Steel Group’s erstwhile honorary chairman, Chang Sang Tae. It specializes in the manufacture and retail of steel products, such as iron plates and galvanized GI steel coils.

DONGKUKCM has a large collection of galvanized steel coils that they produce by using the pickling and rolling method to prevent corrosion. The steel coil has a hardness range of 50–60, 45–55, and 30–40. The yield points are 25–35, 20–30, and 12–30. Their tensile strengths are 35–45, 30–40, and 28–33.

The coils have an elongation of 30-38m, 34-42 m, and 40-48 m. The production of these coils follows the KS, JIS, ASTM, and EN standards.

Established in 2015, POSCO Steel is a steel manufacturer in Pohang, South Korea. In the same year, it produced 42,000,000 metric tons of crude steel, making it the sixth largest steelmaker in the world and, in 2010, the world’s largest. 

POSCO’s EN10147-certified GI steel coil has a tensile strength of A446 Grade A of 310 MPa (N/mm2). Their GI (EDDQ), GI high-tensile steel, GI steel for structural applications, and GI (CQ, DQ, DDQ) have thicknesses of 0.5 to 2.0mm, 0.4–2.0 mm, 0.3 to 2.0 mm, and 0.6 to 2.3mm.

Each has corresponding widths of 600–1700 mm, 600–1850 mm, 600–1800 mm, and 600–1850 mm.

Hanmi Resources Co., Ltd. has over thirty years of experience as an iron and steel manufacturer. It is listed in the Korea Chamber of Commerce and Korea Trade Associations. In the 1990s, Hanmi started sourcing the raw materials from local sources.

Hanresco exports its products to Kuwait, Saudi Arabia, Iran, India, New Zealand, and Australia. Their galvanized (GI) coil sheets have a JIS G 3302 quality with a surface finish of Z (minimized spangle) or R (nominal spangle.).

Hanresco’s coil sheets have a thickness of 0.40–3.00 mm  and widths of 30–1.520 mm. The length is 0.45 mm, with a coil ID of 420–610 mm and a weight of 5–20 MT.

Younsan Metal Company installed its hot and cold-rolled steel systems in 2016 to begin its operation as a steel manufacturer. In the same year, it produced its color steel, core slitter, and tin tube slitter systems. In 2006, it reached export sales of 10 million USD and became an agency of Hyundai HYSCO. 

Younsan’s galvanized GI coil sheets are rust-free due to the zinc composition during the hot dip process. It has excellent workability and paintability, making it a popular choice for roofing. The coil sheets boast of their certifications, consisting of ASTM 89, ASTM 95, EN10142, JIS G3302, and KS D3506.

Daejin Co., Ltd. began its operation on January 25, 1996, as a steel manufacturer. Its headquarters perch in its 1,851.73-square-meter building area. In May 2015, it installed its shearing set and leveler. It has the largest molding machines to produce steel products in Korea.

It is a holder of quality management system, KSA 9001:2001/ISO 9001:2000, and utility model certificates.

Daejin boasts of its galvanized GI coil sheets that they produce at its 6,186-square-meter factory lot. They use the dip-cold-rolled system to produce the coil sheets in a molten zinc bath to protect them from corrosion.

These coil sheets offer excellent paintability, workability, and corrosion resistance.

Sinil Cheolpan (steel plates) was established in November 1989 in Seoul Yeongdeungpo-gu Dorim-dong. It transferred its factory and headquarters on January 1, 1992, to its current location. The company was registered as a corporation in 2011, and its name became Sinil Steel in 2015.

Sinil Steel manufactures galvanized GI steel coils with various dimensions and plating amounts ranging from 80 to 720 g/㎡.  The surface conditions of these coil sheets consist of regular, zero, and ultra. Each type has a zinc composition of Z06~Z60. 

The steel has three types of chemical conversion treatments, such as chromate for general purposes, non-treatment for paintability, and organic film for machinability and anti-fingerprint. 

Kibo Steel Co., Ltd. specializes in the manufacturing and supply of steel products. It began its operation in March 2016 and as a military service company in December of the same year. In 2014, it installed its two factories in Sihwa.

In August 2014, its factory slitter in Dangjin started operating. Kibo Steel owes its success to its professional workers, who are experts in cold and hot-rolled coil operations.

Their galvanized GI coil steel undergoes a continuous hot dip process before passing through a melted zinc bath. Their GI steel coils are in demand in the electrical and automobile industries. They come in regular spangle, mini spangle, and galva.