Sinker bar
After three months of communication, we finally received the order of sinker bar from the customer.
Our customer needed 1-1/2 sinker bar. The customer initially required 7/8 "sucker rod thread on the two ends of polished rod sprayed metal, but the size of 7/8" does not conform to API standard. The API 11B standard requires 1-1/2” sinker bar equipped with 3/4 "sucker rod thread or 7/8" polished rod thread.
After we discussed with our engineers, we provided two options for our customer. One is to provide 7/8 "sucker rod thread, and then we make a pin shoulder to clamp the sucker rod coupling. The other is to provide 7/8" polished rod thread, because the polished rod thread is tapered and can withstand strong tension, so there is no need for pin shoulder. Then we would provide our customer with a sub-coupling, one end of which is connected to the sucker rod and the other end of which is connected to the polished rod
