 1975. | Foundation of Sung Jin Machinery Co., Ltd. |
| 1980. | Supply of Expansion Joint for marine applications to United States, United Kingdom. |
| 1982. | Acquisition of KS (Korean Industrial Standard) |
| 1985. | Production of Flexible Couplings for automotive industry |
| 1990. | Localization of the Expansion Joint (Q-Class) for nuclear power plants |
| 1991. | Completion of the second factory in Banwol industrial complex |
| 1991. | Establishment of the joint-venture company, SJM Flex (M) Sdn. Bhd in Malaysia |
| 1993. | Completion of the third factory in Sihwa industrial complex |
| 1993. | Awarding a prize of the 5 million dollars export |
| 1996. | Renaming of company to SJM CO., LTD. |
| 1996. | ISO 9001 certification |
| 1997. | Listing on stock exchange |
| 1997. | Establishment of SJM FLEX SA (Pty) Ltd. in South Africa |
| 1997. | Establishment of SJM GmbH in Germany |
| 1997. | Acquisition of Seohwa Telecom Co., Ltd. |
| 1997. | QS 9000 certification |
| 2001. | Registration Seohwa Telecom Co., Ltd. at KOSDAQ |
| 2001. | Establishment of SJM North America, INC. in USA |
