C1 Certified Co. ABB India – Vadodara (ISO 3834-2) | C10 Certified Co–SMS India – Khurda (ISO 3834-2) |
| C2 Certified Co. –BHAVINI – Kalpakkam (ISO 3834-2) | C11 Certified Co.-Standard Belex –Faridabad (ISO 3834-2) |
| C3 Certified Co. –Bhiwadi Cylinders – Bhiwadi (ISO 3834-2) | C12 Certified Co. -Tata Growth Shop – Jamshedpur (ISO 3834-2) |
| C4 Certified Co. –Dantal Hydraulics – Manessar (ISO 3834-2) | C13 Certified Co. -North Eastern Railway – Bareily (ISO 3834-2) |
| C5 Certified Co. -Inox –Kalol (ISO 3834-2) | C14 Certified Co. -Central Railway – Parel (ISO 3834-2) |
| C6 Certified Co. -Inox – Kandla (ISO 3834-2) | C15 Certified Co. -TEXMACO R & E –Sodepur (EN 15085-2 CL1) |
| C7 Certified Co. –Plasser – Faridabad (ISO 3834-2) | C16 Certified Co -Plasser India–Faridabad (EN15085-2 CL1) |
| C8 Certified Co. -Indiana Gratings – Pune(ISO 3834-2) | C17 Certified Co. -Apollo Heat Exchangers (EN15085-2 CL2) |
| C9 Certified Co. -Western Railway – Bhavnagar(ISO 3834-2) | C18 Certified Co. –Capital Hi Tech Engineering (ISO 3834-2) |
| C20 Certified Co. –SES Engineering (ISO 3834-2) | C19 Certified Co. –Visiontech Enterprises (ISO 3834-2) |
| C21 Certified Co. –Ved Sassomechanica (ISO 3834-2) | C22 Certified Co. –TEXMACO Agarpara (ISO 3834-2) |
| C23 Matchwell Engineering nov 2019 | |
