Sucker Rod Coupling is a joint for Sucker rod, used in oil well downhole for oil pumping and Production. Yunsheng sucker rod couplings are manufactured from high quality Alloy Steel AISI 5140, fully in accordance with API Spec 11B standard, including class SM coupling, class T coupling, Sub coupling, Full Size, Slim Hole and Over Size, and the thread size are available at 5/8â??, 3/4â??, 7/8â??, 1â?? and 1 1/8â??. SUCKER ROD COUPLING T, SM Nominal Size (in) Outer Diameter +0.13(+0.005)- 0.25(-0.010)(in/mm) Inner Diameter +0.13(+0.005)- 0.25(-0.010)(in/mm) Outer Size(in) O.D.*Length Weight (kg) Full Size 5/8" 1 1/2(38.10) 15/16(23.81) 1.500�?4.000 0.56 3/4" 1 5/8(41.28) 1 1/16(26.99) 1.625 4.000 0.62 7/8" 1 13/16(46.04) 1 3/16(30.16) 1.812�?4.000 0.75 1" 2 3/16(55.56) 1 3/8(34.93) 2.187�?4.000 1.15 1-1/8" 2 3/8(60.33) 1 9/16(39.69) 2.375�?4.500 1.45 Slim Hole 5/8" 1-1/4(31.8) 15/16(23.81) 1.250�?4.000 0.41 3/4" 1-1/2(38.1) 1 1/16(26.99) 1.500�?4.000 0.47 7/8" 1-5/8(41.3) 1 3/16(30.16) 1.625�?4.000 0.52 1" 2(50.8) 1 3/8(34.93) 2.000�?4.000 0.58