Sucker rod coupling have the same box thread size in each end and are used for connecting sucker rods and/or pony rods.

Couplings and Subcouplings are furnished in two classes, Class T and Class SM. Mechanical properties shall be per manufacture's specification with a minimum tensile strength of 95000psi(655Mpa)

Class T----the material shall be per manufacture's specification and shall have a maximum sulfur content of 0.05 percent.

Determination of the metal material hardness as 56 to 62 HRA is an acceptable means to comply with the tensile requirement of 655Mpa.

A certified Material Test Report for the heat of steel from the original mill manufacturer is an acceptable.

Class SM----the base material shall be per manufacture's specification and shall have a maximum sulphur content of 0.05 percent .Spray metal coating hardness shall be 595HV200 minimum.

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.