Yunsheng is the professional manufacturer of API sucker rod couplings and has been in this business for many years.

We got the API certifivate on June 1, 2009. The couplings have been exported to many countries and enjoy high reputation from our customer.

3.API Class SM Full Size sucker rod coupling
7/8"Full Size Spray Metal Sucker Rod Coupling

 1) Material: Seamless Alloy Steel 40Cr (AISI 5140)
 2) Standard: API Spec 11B
 3) Main specification:
   OD:1-13/16" (46.04mm)
   ID: 1-3/16"(30.16mm)
   Length: 4" (101.6mm)
   Weight: 0.74kg
 4)Smoothness: 3.1*10-3
 5)Coat Thickness(in): 0.01in ~ 0.02in
 6)Basic hardness: HRC 16-23
 7)Surface Hardness: HRA 58-62
 8)Intergrate intension(Mpa): 484
 9)Hole rate: <2%
 10)Min. Hardness of the layer: 595HV0.2
 11)Min. Tensile Strength: 655 Mpa
 12)Operating Temperature: -1000~400 centigrade
 13)Life: > 180 days

 14) Package: wooden case, 1000pcs each case.
 15) Usage: oil exploration equipment, accessories, oil sucker rod coupling

4. API Class SM Slim Hole sucker rod coupling

7/8" Slim Hole Spray Metal Sucker Rod Coupling
 1) Material: Seamless Alloy Steel 40Cr (AISI 5140)
 2) Standard: API Spec 11B
 3) Main specification:
   OD:1 5/8" (41.3mm)
   ID: 1 3/16"(30.16mm)
   Length: 4" (101.6mm)
   Weight: 0.52kg
 4)Smoothness: 3.1*10-3
 5)Coat Thickness(in): 0.01in ~ 0.02in
 6)Basic hardness: HRC 16-23
 7)Surface Hardness: HRC 55-62
 8)Intergrate intension(Mpa): 484
 9)Hole rate: <2%
 10)Min. Hardness of the layer: 595HV0.2
 11)Min. Tensile Strength: 655 Mpa
 12)Operating Temperature: -1000°C~400°C
 13)Life: > 180 days

For more information please do not hesttate to contact me.

Yantai Yunsheng Petroleum Machine Accessories Co. Ltd., founded in 2005, is a professional manufacturer of API Spec 11B Sucker Rod Couplings, including Spray Metal coupling, class T coupling, Sub OD coupling, with various type of Full size, Slim Hole, Over Size, with Big Chamfer, with Wrench Flat, with Bidirectional Cambered Surface Protection, etc., and the thread size are available at 5/8", 3/4", 7/8", 1", 1-1/8".  Owning world top level equipments and technicians, the monthly production capacity is more than 20,000pcs.  All of our couplings are excellent in Quality and reasonable in Price, and the production & inspection are being done fully in accordance with API Spec11B standard.