Profile: Tianhe Oil Group Huifeng Petroleum Equipment Co., Ltd. specializes in manufacturing petroleum equipment. We are an ISO 9001:2000 certified company. Our products include drill collars, drill pipes, hydraulic jar testers, hydraulic bucking units, down hole motors, shock absorbers, jars, drilling tools, work-over tools, cementing tools, coring tools, fishing tools and fitting & BOP automatic cleaning systems. Our stabilizers include integral spiral blade stabilizers, non-rotating stabilizers, float valve stabilizers and spherical stabilizers. Our tool joints are made of AISI 4137 premium alloy steel fully, and machined by CNC lathes. All connections are phosphatized, coated with lubricant, and provided with thread protectors. All tool joints are inspected at full length by fluorescence magnetic particle and ultrasonic method. Our inner tooth shoe is mainly used to mill damaged fish top, such as tubing and drill pipe body damaged by upsetting.