Created on 09.23

API 5CT OCTG Casing & Tubing: Specifications, Grades & Applications

API 5CT OCTG (Oil Country Tubular Goods), including casing and tubing, are critical components for oil & gas well drilling and production.
Casing supports well walls and prevents formation collapse during cementing. Tubing sits inside casing to transport oil, gas or injection media. Both products follow strict API 5CT international standards.
Main Steel Grades
• J55 / K55: For shallow, low‑pressure wells, cost‑effective with available stock.
• L80/ N80 / P110: For medium & deep wells, high collapse resistance for high‑pressure conditions.
• L80‑9Cr / L80‑13Cr: Alloy steel for heavy‑corrosion wells with CO₂ and chloride ions.
Threads & Sizes
Common connections: LTC, STC & BTC
• Casing: 4‑1/2″ ~ 20″
• Tubing: 2‑3/8″, 2‑7/8″, 3‑1/2″
Standard length R1 / R2 / R3
Matching couplings of identical steel grade are available for all pipes.
Our Advantages
  1. Integrated factory & Tianjin trading firm, stable price & delivery.
  2. Mass stock for regular sizes; custom production for special requirements.
  3. Full API‑5CT documents: MTC, NDT inspection, hydro‑test reports.
  4. FOB / CIF / CFR trade terms, rich export experience for India, Middle East and Southeast Asia oilfields.
Application Scenarios
On‑land oil & gas fields, deep high‑pressure wells, sour H₂S wells, corrosive gas wells, water wells, geothermal projects etc.