Couplings produced by our factory include sucker rod coupling, sub-coupling, API 5CT tubing and casing coupling. Sucker rod coupling and sub-coupling are designed in accordance with API Spec 11B, the material is high quality alloy steel. Normally, there are 2 wrench flats on the outside diameter. Class T coupling hardness is HRA56-62 after heat treatment, possesing better anti-corrosion property and abrasion-proof property.
Sucker rod coupling is used for connecting the same size of sucker rods. Sub-coupling is used for connecting the two sizes of sucker rods or polished rod to a sucker rod string.
| Size (in) |
3/4 |
7/8 |
1 |
| Coupling O.D (+0.13,-0.25) (mm) |
41.3 |
46.0 |
55.6 |
| Threaded D.(in) |
1 1 /16 |
1 3 /16 |
1 3 /8 |
| Lengh of wrench square (mm) |
31.8 |
31.8 |
38.1 |
| Lengh (+1.57,0.00) (mm) |
101.6 |
| Hardness ( HRA ) |
56-62 |
Audited Supplier 
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