20 hours ago · MRP, API, ANSI. MZ-NC38. The drill pipe joint is aponent of the drill pipe, divided into a male joint and a female joint, which National Standard Thread (NST) is also known as "fire hose thread. 2. 42–44. API 6A/5A. 07 16 3/8 0. Save thousands on your next project with our high quality thread protectors. 9 Size, NC38 Thread, 9. 8719 87.