Coupling

Tubing Upsetting & Short Joint Types 

The thickening (or upsetting) process begins by heating the end of the tubing and then feeding it into an upsetting machine. This causes plastic deformation at the pipe end—the internal diameter remains unchanged, while the outer diameter and wall thickness are increased, along with the effective length of the thickened section.

This is a complex process involving upsetting, expanding, and extrusion. Its main purpose is to improve the mechanical strength of the threaded connection, reduce failure risks, and extend the service life of the tubing during oilfield operations.

Short Joint Types

1. Standard Short Joint

• Includes Flat-End (NUE) and Upset-End (EUE) versions.

• NUE: Direct threading at both ends without thickening.

• EUE: Ends are thickened before threading, providing higher torque resistance.

  
  

2. Double Male Short Joint

Both ends are machined with male threads; no couplings or female connections are used. Suitable for special connections or quick joint operations.

3. Full-Length Upset Short Joint 

Entire length is upset/thickened for better strength and sealing in high-pressure environments.

In-Stock Availability

We maintain a stock of API 5CT certified oil casings and small-diameter thickened tubing joints in sizes from 1.9" to 2-7/8".

Product Names

• Tubing Coupling

• Oil Tubing Coupling

• Thickened Tubing Coupling (EUE)

• Flat Tubing Coupling (NUE)

Technical Specifications

• Standards：
  API SPEC 5CT, API SPEC 5B, API-7

• Steel Grades：
  J55, K55, N80, L80-1, L80-SS, L80-3Cr, L80-13Cr, L80-9Cr, Super 13Cr, P110, P110-13Cr, TP110S, etc.

• OD：
  55.88mm – 141.3mm (1.315" – 4-1/2")

• Thread Types：

• NUE (Non-Upset End )

• EUE (External Upset End)

• SCC (Special Clearance Connection )