| Si Chuan Heben Biotic Engineering Co. Ltd. ( Chengdu, Sichuan Province ) | Si Optical, Inc. | Siam Ball Sport Factory Co., Ltd. ( Amphur Meuang Samutprakarn, TH ) |
| SI Corporation | Si Optical, Inc. ( Allentown, PA ) | SIAM CAST IRON WORKS CO., LTD. ( Samutsakorn, TH ) |
| SI Corporation ( Chickamauga, GA ) | Si Options, LLC ( Dallas, TX ) | Siam Line S.R.L.( Signa ) |
| SI Corporation ( Chickmauga, GA ) | Si/Baker, Inc. ( Easton, PA ) | Siam Safety Empire Co., Ltd.( Chonburi ) |
| SI Diamond Technology, Inc. | SI-1, Inc. ( Conroe, TX ) | Siam Safety Premier Co., Ltd.( Chonburi ) |
| SI Diamond Technology, Inc. ( Austin, TX ) | SI-1, Ltd. ( Conroe, TX ) | Siam Steel |
| SI Diamond Technology, Inc. ( Houston, TX ) | SI2 Technologies, Inc. ( Chelmsford, MA ) | Siamp Cedap ( Monaco, MC ) |
| SI Diamond Technology,Inc. ( Austin, TX ) | SI2 TECHNOLOGIES, INC. ( N. Billerica, MA ) | Siamp-Cedap ( Monaco, FR ) |
| Si Glaz ( Santa Clara, CA ) | SIA "kurs"( Riga ) | Siano Mobile Silicon Ltd. ( Netanya, IL ) |
| SI Group, Inc. ( Schenectady, NY ) | SIA "kurs" ( Riga, LV ) | Siantec Sarl( Tarbes ) |
| Si Han Kim ( Daessangyong-Ri, Choweol-Myun ) | SIA Abrasives Holding AG | SiArc ( Palo Alto, CA ) |
| Si Han Kim( Kyunggi-Do ) | sia Abrasives Holding AG( Frauenfeld ) | SiArc ( Sunnyvale, CA ) |
| SI Handling System, Inc. ( Easton, PA ) | Sia Abrasives Industries AG ( Franuenfeld, CH ) | SIARGO. INC. |
| SI Handling Systems, Inc. ( Easton, PA ) | sia Abrasives Industries AG ( Frauenfeld, CH ) | Sias Equipment Company ( Skokie, IL ) |
| SI Industrial Instruments, Inc. ( Hawthorne, NY ) | SIA Adhesives, Inc. ( Akron, OH ) | Siasprint Group S.r.l.( Novara ) |
| SI JING HARNG CO., LTD. | SIA Syncrosoft ( Riga, LV ) | Siasprint S.r.l.( Milan ) |
| SI O SI ALIMENTOS, S.A. DE C.V. | Sialo-Lite Ltd. ( Asheklon, IL ) | |
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