The tooth profile of the conical thread is triangular, which mainly depends on the deformation of the tooth to ensure the tightness of the thread pair. It is mostly used for pipe fittings. The tapered pipe thread has a taper of 1:16. Because of this feature, the raw material tape wound on the thread can be more evenly distributed on the thread, with better sealing performance. At the same time, the iron pipe wall used for the tapered pipe thread is more Thicker, with higher pressure resistance, so this type of thread is commonly used to seal liquids and gases.

In fact, there is another kind of taper pipe thread called: dry sealing thread, that is, it can be sealed by directly tightening it without any filler. There are two main reasons for its sealing characteristics: 1. Due to the taper, this thread has a "self-tightening effect" when matched with the same tapered thread or cylindrical thread; 2. Its special tooth shape design has " "Complete fit" characteristics (unlike ordinary metric threads, there is a gap between the top of the tooth and the bottom of the tooth-the top of the tooth is flat and the bottom of the tooth is round). In reality, due to many reasons such as processing accuracy, fillers are usually added, such as raw material tape, hemp white paint and so on. Many of the original stresses that commonly cause failure to "dry seal" may include: insufficient tooth profile accuracy (such as angle) (anastomosis), and insufficient end face vertical (referring to matching cylindrical pipe threads)