Our Diameter: 4 1/2" ~ 20" (114.3 mm ~ 508mm) Wall Thickness : as per API 5CT standard ( the latest edition ) Lenght: R1, R2, R3 Steel Grade: H40/J 55/K55/N80/ C75/L80/C90/ T95/ P110/Q125 Pipe Type: Seamless (SMLS), Electric Resistance Welded (ERW) Threads or Connection: LTC/STC/BTC/ Left Hand connection or other premium threads like: VAM Surface Treatment: Anti-corrosion Water Based Paint Packing: Protection Caps on both ends and in bundles with steel strips and two tags as per export requirements Application: Used as the architectural retainer for the walls of oil, gas wells