Engaged in fasteners for many years, do you know the history of the bolt? 

At first glance, the bolt is just the things together, it seems ordinary odd. But go deep down, you will realize that, compared to the first impression, seemingly insignificant bolts and screws behind actually hidden more secrets. Without them, all utensils and machines are fragmented.

Bolts are one of the most commonly used parts in construction and mechanical design. They will be all sorts of things together - from the electric toothbrush and the door hinge of the screws, to a large number of bolts used in building the concrete pillar fixed numerous, all-inclusive. But have you ever stopped to think about where they actually came from?

Germany's "Pola Firearms History" included an article as a draft in 1475 years in the manuscript,  detailed records and draw the earliest Arquebus, the rifle bolt is with two grooved screw fixed in the buttstock.  The reason why theuse of screws, is to deal with the barrel to detonate the gunpowder when the vibration generated, so that the rifle bolt will not be so loose from the buttstock.

The early screws were made by hand. In the production, the first forging out the screw nail embryo, and then hammer in the nail on the knock on the nail head and round nail body;  then, with the saw in the nail head cut a groove, and then use a called "Die" of the screw plate manufacturing thread.

As the production process is complex and expensive, the early screw is on a sell, its application is not extensive. Until the middle of the 16th century, its application areas are limited to armor, guns and watches and clocks, and so few industries.

Although the history of the thread can be traced back to 400 BC,  but it is the most important development of modern bolts and screws in the process in the past 150 years, while the experts held different views on the origins of insignificant nuts and bolts. Frederick E. Graves proposed in his article "Nuts and Bolts" that the history of bolts and matching nuts used as fasteners can only be traced back to the 15th century. He made the conclusion based on the first time in a book in the early fifteenth century that he had recorded in printed form.

However, Graves also admitted that although the bolts could be traced back to the 15th century, but no threaded bolts can be traced back to the Roman era,  When the bolt is used to latch the door as the door and the wedge of the wedge bolt: a notch on the bolt or screw, which allows the wedge to be inserted, so that the bolt can not move. "He also said that the Romans used bronze and even silver to make the first screw. The thread is made by hand, or the metal wire is wound around the screw, and the thread is formed after welding.

According to bolt expert Bill Eccles study, the history of the screw thread is even earlier.Archimedes discovered the principle of the spiral and used to build the water lifting equipment. However, there are indications that the spiral pump may have been born in Egypt for time earlier than Archimedes. The equipment is constructed of wood and is used to irrigate the land and discharge the sewage from the bilge. Eccles wrote on his website: "But many people think that the screw thread was invented by the Greek philosopher Alcitas around 400 BC, and Alchtas was known as the founder of the mechanics and belonged to the same era as Plato "

Archimedes

History can be divided into two parts: around 400 BC, the screw thread came out, people use it to carry water, squeeze grape juice,etc; and the fastener itself is about the history of about 400 years. Enter fifteenth Century,Gutenberg used screws in the fasteners of his press. Then, the trend of the use of screws is becoming wider and wider, and the scope of application is extended to the clock and armor.According to Graves, Leonardo da Vinci's notebooks in the late 15th century and early 16th century contained some designs for thread-cutting machine tools.

Germany "Wolfgang Castle Medieval Family Book" recorded in the world's first screw cutting machine. The book is painted with a screw to connect the metal picture, which shows that at least in the 15th century when the screws have appeared.

But on this topic, most researchers agree that the industrial revolution has accelerated the development of nuts and bolts and made them an important part of engineering and construction.

WR Wilbur admitted in 1905 the history of the American nut and bolt industry that the first machine used to make bolts and screws was made in France by Besson in 1568 , Besson later introduced thread cutting teeth Rules or screw die, used in lathes. In 1641, the British company Hindley of York on the equipment has been improved, so that it is widely used.

In 1579, Jacques Besson designed the screw cutting lathe.

In the United States on the other side of the Atlantic, the history of the bolt can be found in the Carriage Museum of America. In the early nineteenth Century, the nuts on the vehicle were more flat and square than the later ones, and the later nuts were chamfered, and the bolts were machined into a flat shape. During this period, the production of bolts is a tedious and arduous process.

The threads of the fasteners were initially made by hand, but it was not long before the need to speed up the production process due to the surge in demand. 1760 in the UK, J and W Watt introduced the factory manufacturing process, mass production of screw threads. However, this significant development brings another challenge: every company produces its own threads, nuts and bolts, so the market is filled with a lot of different sizes of threads, to the machinery manufacturers bring a lot of trouble.

Until 1841, Joseph Whitworth successfully found the solution. After years of research and collection of sample screws for many British factories, he proposed to develop a standard for thread size of Britain,  so that manufacturers in England and Glasgow manufacturers of bolt nut can use together.His proposal is that the angle of the thread face is 55 degrees, and the number of threads per inch should be defined according to different diameters.

When the problem was resolved in the UK, the Americans were trying to solve the same problem and started using Wyeth thread. In 1864, William Sellers made a 60 degree thread and a variety of pitch, applicable to different diameters. Which later developed into the American standard of coarse teeth series and fine teeth series. Compared to the British standard, one of the advantages of the American standard is that their threaded teeth have flat teeth and crested tops. Compared to the Wyeth standard with rounded teeth and crests, it is easier to produce. However, it is found that Wyeth thread in the dynamic application of the performance is better, and Wyeth thread round teeth can improve the aging problem.

During the First World War, the lack of uniform standards in different countries of the thread, as a major obstacle to the war; during the Second World War, the Allies, the problem has become more serious. In 1948, the United Kingdom, the United States and Canada agreed on uniform standard threads and used as a standard for all countries that use imperial units. The standard uses a tooth type similar to the DIN metric thread developed by Germany in 1919 and is the best combination of Wyeth thread type and Sellers thread. However, the uniform standard thread of the tooth radius is longer, proved to be more favorable than the DIN metric thread type. This has led to the generation of ISO metric threads, which is the standard widely used in all industrialized countries today.

In recent decades, people working in this industry have witnessed many of the bolts' adjustments. Eccles recalled: "I started to get involved in this industry 35 years ago, when the advantages of bolts were not so obvious today. With the introduction of modern metric categories and recent updates to the relevant ISO standards,It is now more clear about the advantages of the bolt and the methods used to determine its characteristics, are more clear. "

As the raw materials industry has become more developed, the bolt of DNA from steel into other more innovative materials to meet the ever-changing industry needs. Over the past 20 years,  the development of nickel based alloys.  Ni-based alloys can work in high temperature environments, such as turbochargers and engines, while steel in the environment is poor performance. Recent studies have focused on light metal bolts such as aluminum, magnesium and titanium.

Today's bolt technology compared to manually manufactured bolts and screws,as well as customers can only choose alkaline steel nuts and bolts,there has been considerable development.. Today, many companies have made significant improvements in bolt technology, including wedge lock systems. Customers can choose pre-installed zinc coating or stainless steel washers, wheel nuts designed for flat steel rims or combination bolts for different applications.

Now, people are more emphasis on analysis of joints. Eccles explained: "In the past, people used to only according to their own experience to determine the size of fasteners, and then hands together to pray for its effectiveness.Nowadays, people pay more attention to the manufacture of products and to market before the analysis and ensure product performance work "