Yantai Yunsheng Petroleum Machine Accessories Co. Ltd., founded in 2005, is a professional manufacturer of API Spec 11B Sucker Rod Couplings, including Spray Metal coupling, class T coupling, Sub OD coupling, with various type of Full size, Slim Hole, Over Size, with Big Chamfer, with Wrench Flat, with Bidirectional Cambered Surface Protection, etc., and the thread size are available at 5/8”, 3/4”, 7/8”, 1”, 1-1/8”. Owning world top level equipments and technicians, the monthly production capacity is more than 20, 000pcs. All of our couplings are excellent in Quality and reasonable in Price, and the production & inspection are being done fully in accordance with API Spec11B standard. We got our API Spec 11B Certificate for couplings since last June, the Certificate No. is 11B-0088, and we began our International sales since then. Only one year, we have exported our couplings to America, Peru, Argentina, Kuwait, India, Indonesia, etc., and have established longterm cooperation with many of our customers home and abroad, based on our good quality and Service. Meantime, we have been the golden Member of Alibaba.com for nearly two years, showing you more of us online, and hoping to be your best supplier and good friend in China.