API OTCG Tubing Coupling

  • Standards: API 5CT
  • Processing: Seamless
  • Size: 2 3/8- 4 1/2”
  • Grade: J55, K55, L80, N80, P110
  • Thread Type: NUE, EUE
  • Test: NDT etc related rules of API 5CT and 5B
  • Surface Treatment: Whole phosphating, or inside phosphating and outside coating

API Tubing Coupling Overview

OTCG (Oil Country Tubular Goods) is a family of rolled metal products for oil and gas drilling. These include drill pipe, casing and tubing, line pipe, couplings and connections. Tubing couplings are short lengths of pipes applied to connect two joints of casing pipe or tubing used in drilling, piling and mining operations to reduce the transmission of shock loss from one shaft to another. They can also be used to connect a drilling par to a driven part. They are painted with different color codes on the external surface to indicate their grades. The material grade of the tubing coupling should match the pipe body grade and PSL if applicable. It should also be manufactured with the same heat treatment as the pipe body. 

compared with casing coupling, tubing coupling has a maximum outer diameter of 4 1/2 inch, while casing coupling is more than 4 1/2 inches the tubing pipe is applied for the drilling activities (Inside the tubing). API Tubig couplings have various threads, mostly used is thicken type external upset coupling(EUE, EU end or UP TBG coupling) and nonupset end (NUE, NU end, or TBG). Wiho metals is a quality wholesale manufacturer and supplier of OCTG Casing and Tubing in China that can offer you a wide variety of API prime OCTG Tubing and Casing Couplings. We have a large supply of in-stock inventory manufactured according to API standards and used for oil production activities onshore and offshore. As a good OCTG manufacturer, we will be able to offer you a wide variety of coupling sizes and grades, and excellent service at reasonable prices.


Size, inch



2 3/8

2 7/8

3 1/2

4 1/2






External upset end(EUE)

Non upset end(NUE)


API Tubing Couplings Dimension(EUE)

Casing Size, OD, inch Coupling size, OD, inch Threads per inch Length, inch Weight per Coupling (lbs)
1.90 2.500 10 Round 1.85
2-3/8 3.063 8 Round 4.875 3.42
2-7/8 3.668 8 Round 5.500 5.29
3-1/2 4.500 8 Round 5.750 9.02
4 5.000 8 Round 10.62
4-1/2 5.563 8 Round 6.500 13.31

API Tubing Couplings Dimension (NUE)

Casing Size, OD, inch Coupling size, OD, inch Threads per inch Length, inch Weight per Coupling (lbs)
1.90 2.200 10 Round 3.750 1.85
2-3/8 2.875 10 Round 4.500 2.82
2-7/8 3.500 10 Round 5.500 5.15
3-1/2 4.250 10 Round 5.625 8.17
4 4.75 8 Round 5.75 9.57
4-1/2 5.200 8 Round 6.500 10.76


For more information on our extensive size and inventory, please contact us or fill in the form below.

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