API-standard adapter couplings are designed for use in rock drilling and breaking, anchoring drill holes, oil exploration, and geological well-drilling operations. They serve as critical tools for connecting upper and lower drill string components, playing a key role in linking the top and bottom sections of the drilling assembly. Our company offers a wide range of adapter coupling solutions tailored to meet diverse application needs. These couplings are crafted from high-quality materials such as 35CrMo, 42CrMo, and 40CrMnMo. After rough machining, they undergo tempering heat treatment, followed by precision surface nitriding after finishing. This advanced manufacturing process effectively minimizes risks of thread galling, thread breakage, and outer diameter expansion—issues that can lead to failure—while enhancing wear resistance and ensuring easy disassembly. All adapters are produced using state-of-the-art imported CNC lathes equipped with custom-designed threading tools, guaranteeing both precise thread pitch and consistent dimensional accuracy across every component. This meticulous approach ensures optimal tightness, superior interchangeability, and unmatched reliability in every connection.