- MetalTech Co., Ltd.
- Address:# 301 STARTOWOERS BUILDING, 76-1, SANGNAMDONG
- se young engineering co.
- Address:Rm716, River Tower Officetel 94-119, Youngdeungpo-dong 2ga, Youngdeungpo-ku,
- TOP DRILL INTERNATIONAL CO LTD
- Address:3Ba-120, Sihwa Industrial Complex, 2182-16, Jeongwang-dong
- Taeshin Heavy Ind. Cp., Ltd.
- Address:577-1,Dongpyeong-ri,Gunseo-myeon ,Okcheon-gun
- Hanjin Drilling Co., Ltd.
- Address:1612 Jidong 76 Soongin-Dong, Jongno-Gu
- Daeseung International Co., Ltd.
- Address:3f, Jeongwon B/D,1566-8 Seocho-dong, Seocho-gu
- DNHI Co., Ltd
- Address:6,Hwanhui3-gil, Oksan-myeon
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