API 7/8" Class SM Full Size Sucker Rod Coupling with Big Chamfer,can slow down the wear,reduce the contact area with pipeline

   Based on the spray metal, with big chamfer increases a big chamfer at both ends, greatly reducing the contact area with the pipeline, but also slowing down the wear. So it can not only protect itself better, but also the pipeline. So that the life of the coupling and pipeline are significantly prolonged, and the operating costs of oil reduced, oil production increased.

API Sucker Rod Coupling with Big Chamfer

Standard: API Spec 11B    

Basic Material: AISI 5140 (40Cr)

            Coat Material: Ni60A Alloy Coating                    

Coat Thickness: 0.01-0.02 in

Basic Hardness: HRC 16-23 (HRA 58-62)                          

Surface hardness: HRC 55-62

Metal coating hardness: 595 HV0.2

Hole rate: 2%

Coupling diameter: 5/8 ", 3/4", 7/8", 1", 1-1/8"

Life: 180days

sucker rod couplings :

    Sucker rod couplings are a key component in the successful performance of a sucker rod string. By minimizing the wear and corrosion of couplings, the life of the sucker rod string is increased. This can substantially decrease service and repair costs. Dura Products has set an industry standard with the design of the Premier Performance Sucker Rod couplings including both API Class T (through hard) and API Class SM (spray metal) designs.

For excellent service in mild well environments the API Class T Coupling is the ideal choice. The Class T coupling is manufactured with a through hardiness of between 16 and 23 Rc. This results in high tensile and fatigue strength for the coupling. The outside diameter is smooth to minimize stress concentrations, and an accurate chamfer allows for controlled contact stress. The threads are rolled full form which results in compressive stresses at the thread root and improved fatigue resistance.

For harsh well environments the API Class SM Coupling is the proven leader, especially where severe wear and corrosion is a problem. The Class SM Coupling is also manufactured with a core hardness of between 16 and 23 Rc. This results in high tensile and fatigue strength similar to the Class T coupling. A nickel-chrome based coating [0.012"(0.3mm) minimum thickness] is thermally fused to the outside diameter. This results in a surface hardness ranging between 58-62 Rc which increases wear and corrosion resistance. The outside diameter is ground to a smooth finish and the coupling is inspected to ensure that there are no pinholes or cracks in the surface coating.