The English word for Screw is screw. The meaning of this word has changed greatly in recent hundreds of years. At least in 1725, it means “mating”.Therefore, this is the choice rock bolt The reason, there is no denying its positive impact. https://www.chinatianlong.com/

　　The application of the thread principle can be traced back to 220 BC, when the Greek scholar Archimedes created the spiral water lifting tool.

　　In the 4th century A.D., Mediterranean countries began to apply the principle of bolts and nuts to the press for wine making. At that time, the external threads were all wrapped around a cylindrical bar with a rope, and then carved according to this mark, while the internal threads were often formed by hammering with soft materials wrapped around the external threads.

　　Around 1500, in the sketch of thread processing device drawn by Italian Leonardo da Vinci, there was an idea of using mother screw and exchange gear to process threads with different pitches. Since then, the method of mechanical thread cutting has developed in European watch manufacturing industry.

　　In 1760, the British brothers J. Wyatt and W. Wyatt obtained a patent for cutting wooden screws with a special device. In 1778, an Englishman, J. ramsden, made a thread cutting device driven by a worm gear pair, which could process long threads with high precision. In 1797, H. Maudslay, an Englishman, turned metal threads with different pitches on the lathe improved by him, which laid the basic method for turning threads.

　　In the 1820s, Maudslay produced the first batch of taps and dies for thread processing.

　　At the beginning of the 20th century, the development of automobile industry further promoted the standardization of threads and the development of various precise and efficient thread processing methods. Various automatic opening die heads and automatic shrinking taps were invented one after another, and thread milling began to be applied.

　　In the early 1930s, thread grinding appeared.

　　Although the thread rolling technology was patented in the early 19th century, it developed slowly because of the difficulty in mold manufacturing. It was not until the Second World War (1942 ~ 1945) that the demand of ammunition production and the development of thread grinding technology solved the precision problem of mold manufacturing, and it achieved rapid development.

　　Threads are mainly divided into connection threads and transmission threads.

　　For connecting threads, the main processing methods are tapping, threading, turning, rolling and rubbing.

　　For transmission thread, its processing methods are mainly: rough turning-grinding, cyclone milling-rough turning, etc.

　　Today, let’s take a look at the various processing methods of threads with Xiao Bang and see which method is better.