... :Grade A Certificate:ISO9001:2000 Material: carbon stee ,stainless steel ,forged carbon steel ,alloy Product DescriptionFRD Steel Pipes Steel Pipe Features ... , DIN, JIS, BS, EN, GB, API 6. Productive Technology: Hoe rolling, Cold rolling, Cold drawing 7. Surface Treatment: Polishing, Pickling, Antiseptic, Abrasive blasting, HDG ...