1)Function: The sub sucker rod couplings are used to connect two varisized sucker rod.            

2)Basic Material: High quality carbon steel AISI 5140(40Cr)

3)Type: Spray metal/ T, Full size/ Slim Hole

4)SM Coating Material: Ni60A Alloy Coating

5)Coat Thickness: 0.01in ~ 0.02in

6)Smoothness: 3.1*10-3

7)Basic Hardness: HRC 16-23

8)Surface Hardness: HRC 55-62

9)Hole rate: 2%

10)Min. Hardness of the layer: 595HV0.2

11)Coupling diameter: 5/8"to3/4 ", 3/4"to7/8". 7/8"to1", 1"to1-1/8"

12)Life: 180days

13)Main Specification of 3/4"to 7/8" sucker rod coupling

Weight: 0.92kg

O. D.: 1-13/16(46.04mm)

Length: 4in(101.6mm)