History

1948 Established Shonan Plastics Mfg. Co., Ltd.   Start Plastic Molding Processing Industry
1954 Established Shonan Plastics Mfg. Co., Ltd.
1955 Established a Mold Factory
1984 Established Ibaraki Factory
1991 Established Ibaraki Yasato Factory / Started Construction Related Business
1996 Establish Thailand Factory / Shonan Gousei (Thailand) Co., Ltd. / Obtained Construction Business License 
1998 Established Ibaraki Kakioka Factory
2004 Established SIS ENG (changed company name to SGK Co., Ltd. in November 2020)