Technical specifications: Outer diameter: 60-508mm Standards: API, SEPC, 5CT 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 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 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.