Our company produced coupling including sucker rod coupling,sub-coupling and spray coupling, they are design according to API Spec 11 B standard.Using the high quality carbon steel or alloy steel (the equivalent of AISI 1045 and AISI 4135) and plating metal is a kind of surface hardening technology, is the nickel, chromium, boron and silicon powder coated on the substrate metal and fused with the laser processing, after the process, the metal surface makes harder,density higher and more uniform, the friction coefficient is very low and the corrosion resistance is very high. Slim hole (SH) diameter and standard size (FS) of conventional sucker rod and polished rod have plating metal (SM) .Under normal circumstances, there is two wrench on the coupling and the outside circle, but according to user we can also provide no wrench square.Hardness of coupling T  is HRA56-62  after heat treatment, with good corrosion resistance and wear resistance, when using sucker rod coupling,is connecting with the same size rod, sub-coupling is used for connecting to difference size of the sucker rod or connect the polished rod and rod string .Coupling type: Class T (full size and slim hole ) ,Class SM (full size and slim hole ).

chemical composition

Nominal Size		5/8 in.		3/4 in.		7/8 in.		1 in.		1-1/8 in.
												in.	mm	in.	mm	in.	mm	in.	mm	in.	mm
		Full Size Sucker Rod Coupling、Full Size Polished Rod Coupling and Full Size Sub-Coupling
		ODª Outsside Dimension	Size	1.5	38.1	1.625	41.28	1.812	46	2.187	55.6	2.375	60.33
Tolerance	0.005													0.13	0.005	0.13	0.005	0.13	0.005	0.013	0.005	0.13
	-0.01		-0.25	-0.01	-0.25	-0.01	-0.25	-0.01	-0.25	-0.01	-0.25
	Size		4	101.6	4	101.6	4	101.6	4	101.6	4.5	114.3
Lª
Length	Tolerance	0.062	1.57	0.062	1.57	0.062	1.57	0.062	1.57	0.062	1.57
		0	0	0	0	0	0	0	0	0	0
D2ª	Size	1.365	34.67	1.49	37.82	1.677	42.6	1.99	50.55	2.177	55.3
Minimum
D3ª;	Size	1.11	28.19	1.253	31.83	1.378	35	1.566	39.78	1.753	44.53
												Tolerance	0.015	0.38	0.015	0.38	0.015	0.38	0.015	0.38	0.015	0.38
	-0.055	-1.39	-0.073	-1.85	-0.073	-1.85	-0.073	-1.85	-0.073	-1.85
	BC1ₑ  Maximun	Size	0.0625	1.59	0.0625	1.59	0.0625	1.59	0.09375	2.38	0.9375	2.38
Slim Hole Sucker Rod Coupling、Slim Hole Polished Rod Coupling and Slim Hole Sub-Coupling
	Size	1.25	31.8	1.5	38.1	1.625	41.3	2	50.8
ODª
Outsside Dimension	Tolerance	0.005	0.13	0.005	0.13	0.005	0.13	0.005	0.013
		-0.01	-0.25	-0.01	-0.25	-0.01	-0.25	-0.01	-0.25
	Size	4	101.6	4	101.6	4	101.6	4	101.6
Lª
Length	Tolerance	0.062	1.57	0.062	1.57	0.062	1.57	0.062	1.57
		0	0	0	0	0	0	0	0
D2ª	Size	1.177	29.9	1.427	36.25	1.552	39.42	1.927	48.95
Minimum
	Size	1.09	27.69	1.253	31.83	1.378	35	1.566	39.78
D3ª	Tolerance	0.015	0.38	0.015	0.38	0.015	0.38	0.015	0.38
		-0.035	-0.89	-0.073	-1.85	-0.073	-1.85	-0.073	-1.85
BC1ₑ Maximun	Size	0.03125	0.79	0.03125	0.79	0.03125	0.79	0.03125	0.79
a As shown in figure C.1
b The nominal size of the coupling is the same size as the sucker rod
c Slim hole coupling is the reduces of the outer diameter
d The size of the outer diameter and length shall be determined by the maximum thread size
e See figure c.2. The type is selected by the manufacturer
f For the full size and slim hole diameter coupling of 1 inch L=4.500in.(114.3mm)
g For the full size sub-coupling of 1-1/8 inch L=5.000in.(127.0mm)

Coupling Chemical Component
AISI	C	Si	Mn	P	S	Cr	Ni	Mo	V	Cu	Al
1541	0.36-0.45	0.15-0.35	1.35-1.65	≤0.04	≤0.04	≤0.3	≤0.35	≤0.06	0.04-0.09	≤0.35	≤0.035
5140	0.38-0.45	0.17-0.37	0.4-0.7	≤0.025	≤0.025	0.8-1.1	≤0.3	/	/	≤0.2	/
4135	0.32-0.40	0.17-0.37	0.4-0.7	≤0.025	≤0.025	0.8-1.1	≤0.3	0.15-0.25	/	≤0.2	/
4120	0.17-0.24	0.17-0.37	0.4-0.7	≤0.025	≤0.025	0.8-1.1	≤0.3	0.15-0.25	/	≤0.2	/

Tensile Strength（MPa）	Yield Strength（MPa）	Elongation （%）	Reduction of Area（%）
≥655	≥405	≥16	≥48

Hardness	GRADE T	GRADE SM
	56HRA-62HRA	＞595HV200

Hardness	GRADE T	GRADE SM
	56HRA-62HRA	＞595HV200