Introduction

The suck rod couplings are used for connecting sucker rods, polished rods and sinker bars. Material of the couplings is high quality carbon steel or alloy steel, which are conform to and exceed the requirements of API Specification 11B.

Production

• The sucker rod couplings are manufactured in their own dedicated line.
• Cleaned → prepared → loaded on mandrels → shot blasted → flame sprayed → induction fused.
• The flame spray process is a computer controlled, menu driven operation that holds spray application
• tolerance to within two thousandths of an inch.

Classification

• The main types of sucker rod couplings are sucker rod couplings, polished rod couplings and sub-couplings.
  • Sucker rod couplings has same box thread size in both end.
  • The polished couplings are designed to connecting polished rod and sinker bars.
  • The sub-coupling is also called cross over coupling. It has different box thread size in both end.
  

  Sucker rod coupling has same box thread size in both end.

  

  Sub-coupling has different box thread size in each end.

  

  Polished rod coupling has same box thread and vanish cone in both end.

• All of the three types have two classes: class T and class SM.
  • The class T stands for Through-hardened.
  • The class SM stands for sprayed metal.
• The outer diameter of the sucker rod couplings has full size and slim hole types.
• According to the surface of the suck rod couplings, it can be divided into smooth surface suck rod couplings and suck rod couplings with two wrench square.

Specification

• Material: high quality carbon steel or alloy steel. (AISI 1045, AISI 4135).
• Thread size: 5/8", 3/4", 7/8", 1" and 1-1/8".
• Length: 4", 4.5" and 5".
• Grade: T and SM.
• Type: sucker rod coupling, polished coupling and sub-coupling.

Sucker rod couplings specification

Item	Spec	Internal thread spec	Length	Outside diameter
				Full size	Slim hole
ESRC-01	5/8"	15/16"	4"	38.1mm	31.8mm
ESRC-02	3/4"	1-1/16"	4"	41.3mm	38.1mm
ESRC-03	7/8"	1-3/16"	4"	46mm	41.3mm
ESRC-04	1"	1-3/8"	4"	55.6mm	50.8mm
ESRC-05	1-1/8"	1-9/16"	4.5"	60.33mm	N/M

Sub-couplings specifications

Item	Spec	Internal thread spec		Length	Outside diameter
		Small end	Big end		Full size	Slim hole
ESC-01	5/8" × 3/4"	15/16"	1-1/16"	4"	41.3mm	38.1mm
ESC-02	3/4" × 7/8"	1-1/16"	1-3/16"	4"	46mm	41.3mm
ESC-03	7/8" × 1"	1-3/16"	1-3/8"	4.5"	55.6mm	50.8mm
ESC-04	1" × 1-1/8"	1-3/8"	1-9/16"	5"	60.3mm	N/M

Polished rod couplings

Item	Spec	Internal Thread Spec	Length	Outside Diameter		Vanish Cone
				Full Size	Slim Hole
EPRC-01	5/8"	15/16"	4"	38.1mm	31.8mm	9°
EPRC-02	3/4"	1-1/16"	4"	41.3mm	38.1mm	9°
EPRC-03	7/8"	1-3/16"	4"	46mm	41.3mm	9°
EPRC-04	1"	1-3/8"	4"	55.6mm	50.8mm	9°
EPRC-05	1-1/8"	1-9/16"	4.5"	60.3mm	N/M	9°

Package

• The sucker rod couplings have two type of package.
• In plastic paper and carton.
• In wooden box.

Features

• Good corrosion and wear resistance.
• Black oxide coated for anti-galling and lubricating properties.
• Automatic flame spray production minimize the tolerance.

Application

The sucker rod couplings are widely used in the oil industries for connection for sucker rod, polished rod, pony rod and sinker bars.

• The sucker rod couplings are used for connecting the sucker rod and sinker bars with the same dimensions. But it is not used in the polished rods, which may cause the fracture of the couplings.
• The polished couplings are designed to connect the polished rod and sinker bars.
• The sub-coupling is widely used for the connection of different sizes of sucker rod, pony rod and sinker bars.