1results about How to "Smooth welding surface" patented technology

This invention discloses an internally threaded steel pipe, its processing technology, and processing device. The internally threaded steel pipe includes a stainless steel inner tube (1), which is formed by rolling stainless steel strip. The inner wall of the stainless steel inner tube (1) is provided with thread teeth (2). The number of thread teeth (2) is multiple and they are distributed in a ring along the inner wall of the stainless steel inner tube (1). A thread groove is formed between adjacent thread teeth (2). This invention can reduce the production cost of internally threaded pipes for air conditioners and improve their service life.