- Kumsung Diamond Co., Ltd.
- Address:662-6,Gojan-dong ,Namdong-gu
- TOP DRILL CO., LTD
- Address:3ba-120, Sihwa Industrial Complex, Jeongwang-Dong
- DOWIN INTERNATIONAL CORP.
- Address:# 907, ZelzoneTower I, 17-1, Jeongja-dong, Bundang-gu
- Shani trades
- Address:Seo-gu Seoknam-dong
- T.I. Technology Inc.
- Address:Industrial Center# 23-210, 295, Songrim-dong, Dong-gu
- NOVA R & E
- Address:457-1 Bangsan-dong,
- KORMAX CORPORATION
- Address:237-11, Jangan-Dong, Dongdaemoon-Ku,
- MunWha Chemical
- Address:
- DRILL TECH CORP
- Address:984
- Jeonil Machinery Co., Ltd.
- Address:# 432-1 Seocktan-Ri, Haseong-Myeon