Technical specifications: Outer diameter: 114.3-508mm Standards: api sepc 5ct, 5b Steel grades: h40, j55, k55, n80, l80, c90, c95, t95, p110, q125 Connection: stc, ltc, btc and premium connection Inspection: sgs, bv Certification: iso 9001:2000 Delivery lead-time: after received deposit 10-60 days according to the quantity Payment terms: t/t, 100% l/c at sight Port of shipment: shanghai port, qingdao port or other main ports as per requested Quality control: Company has perfect quality assurance system, advanced testing equipment and high-qualified management team with control over series of activities such as contract signing, product research and development, productive process and test, product preservation and delivery 1. Inquiry evaluation: All technical data of each inquiry must be evaluated by company professional expert and get confirmation by our cooperation mill, we can confirm that all the technical data can satisfy the client's requirement and related standard 2. On-line production supervision: Online production supervision can cover the entire production process, in accordance with the contract requirements and technical specifications Supervision is begin from the re-examination of raw materials, process assessment, the production of internal control, test items, mark, packing and all the other aspects of a full range of production 3. Final product inspection: Detection of the product in accordance with international and national standards, including: the physical performance testing, chemical analysis, nondestructive testing, reliability testing and packing report 4. Logistics survey: Monitor product handling, storage, strapping, transport loading and other logistics chain