At first glance, the bolts just tie things together and it seems ordinary. But as you go deeper, you will realize that there are more hidden secrets behind seemingly insignificant bolts and screws than first impressions. Without them, all appliances and machines will be fragmented.
Bolts are one of the most commonly used parts in architectural and mechanical design. They link everything together - from screws in electric toothbrushes and door hinges, to bolts used to secure concrete pillars in buildings - all in all. However, have you ever stopped to think about where they actually come from?
History of bolts
Although the history of threading can be traced back to 400 BC, the most important developments in the modern bolt and screw process have been made over the past 150 years, and experts have different views on the origins of the insignificant nuts and bolts. Frederick E. Graves in his article "Nuts and Bolts" proposed that the history of threaded bolts and matching nuts used as fasteners dates back to the 15th century. He came to this conclusion based on the first occurrence of printed screws in a book in the early 15th century.
However, Graves also admitted that although the threaded bolt can be traced back to the 15th century, the unthreaded bolts can be traced back to Roman times, when the bolts were used to "batch the door, as the hinge of the opening and closing door and the wedge bolt: on the latch bar or screw With a notch, the wedge can be inserted to prevent the bolt from moving.” He also said that the Romans used bronze or even silver to make the first screw. The thread is manually laid down, or the wire is wound on the screw first, and the thread is formed after welding.
According to bolt expert Bill Eccles's research, the history of threading is even earlier. Archimedes (287 BC - 212 BC) discovered the principle of spirals and used them to build water lifting equipment. However, there are indications that the spiral pump may have been born in Egypt before the Archimedean period. The equipment was constructed of wood and was used to irrigate the land and discharge sewage from the bottom of the ship. Eccles wrote on his website: "But many people think that the thread was invented by the Greek philosopher Archytas of Tarentum around 400 BC. Al-Hitas is called the founder of mechanics. It belongs to the same age as Plato."
History can be divided into two parts: Before and after 400 BC, threads were introduced. People used it to lift water, squeeze grape juice, etc. The history of fasteners itself was about 400 years. In the 15th century, Johann Gutenberg used screws in the fasteners of his presses. Then, the use of screws is becoming more and more widespread, and the scope of use has expanded even more to items such as clocks and armor. According to Graves, Leonardo da Vinci's notebooks in the late 15th and early 16th centuries contained some designs for thread cutting machines.
But on this topic, most researchers agree that the Industrial Revolution has accelerated the development of nuts and bolts and made them important components in the engineering and construction fields.
WR Wilbur acknowledged in the "HISTORY OF the Nut and Bolt Industry in America" published in 1905 that the first machine used to make bolts and screws was made by Besson in France in 1568. Besson later introduced thread cutting gauges or dies for lathes. In 1641, the British company Hindley of York improved the equipment and made it widely used.
In the United States on the other side of the Atlantic, historical records of bolts can be found in the Carriage Museum of America. Nuts used in vehicles in the early 19th century were flatter and later than the later, and later nuts were chamfered and the bolts were machined into flat heads. During this period, the production of bolts was a tedious and arduous process.
The threads of the fasteners were initially made by hand, but not long afterwards, due to the large increase in demand, it is necessary to speed up the production process. In the United Kingdom in 1760, J and W Wyatt introduced a factory manufacturing process to mass produce threads. However, this major development has brought another challenge: each company produces its own threads, nuts and bolts, so the market is filled with a large number of different sizes of threads, giving machinery manufacturers a lot of trouble.
Until 1841, Joseph Whitworth succeeded in finding a solution. After many years of research and collection of sample screws from many British factories, he suggested setting a standard for the thread size in the United Kingdom so that the bolts produced by the England factory and the nuts produced by the Glasgow factory could be used together. His proposal is that the angle of the thread surface is based on 55 degrees, and the number of thread locks per inch should be defined according to different diameters.
When this problem was solved in the United Kingdom, Americans were also trying to solve the same problem and started using the Wyeth's thread. In 1864, William Sellers proposed a 60 degree thread profile and a variety of pitches that can be applied to different diameters. This later developed into the American standard coarse tooth series and fine tooth series. One of the advantages of U.S. standards over British standards is that their thread profile has flat roots and crests. It is easier to produce than the Wyeth standard with a rounded base and crest. However, it has been found that Wyeth's threads perform better in dynamic applications, and that the round teeth of Wyeth's thread can improve the aging problem.
During the First World War, the lack of uniform standards for threads in different countries became a major obstacle to the war of resistance; during the Second World War, the issue became even more serious for the Allied forces. In 1948, the United Kingdom, the United States, and Canada agreed on a unified standard thread and used it as the standard for all countries that use imperial units. The tooth profile used in this standard is similar to the DIN metric thread developed in Germany in 1919. It is a Wyeth thread profile (circular tooth bottom for improved aging problems) and a Celes screw thread (60 degree flank angle and flat crown). The best combination. However, the longer base radius of the uniform standard thread has proven to be more favorable than the DIN metric thread form. This led to the creation of ISO metric threading, which is the standard widely used in all industrialized countries today.
In recent decades, people working in this industry have witnessed many adjustments in bolts. Eccles recalled: “I started to get involved in this industry 35 years ago, when the advantages of bolts were not as obvious as they are today. With the introduction of the modern metrics category and the recent updates to relevant ISO standards, the bolt strengths are now described and used. The test methods to determine its characteristics are all clearer."
As the raw material industry has become more developed, the DNA of bolts has also changed from steel to other novel materials to meet the ever-changing industry demands. Nickel-base alloys have developed in the past two decades. Nickel-based alloys can operate in high temperature environments such as turbochargers and engines, and steel performs poorly in this environment. Recent research has focused on light metal bolts such as aluminum, magnesium and titanium.
Today's bolting technology has grown considerably compared to hand-made bolts and screws, and customers can only choose alkaline steel nuts and bolts. Today, companies such as Nord-Lock have made significant improvements in bolting technology, including wedge-locking systems. Customers can choose from pre-installed zinc-coated or stainless steel washers, wheel nuts designed for flat-bottomed steel rims, or custom bolts for different applications. Acquired US company Superbolt Inc. and Swiss company P&S Vorspann systeme AG (now Nord-Lock AG) to increase the number of bolts used in heavy industry (such as offshore energy and mining) in Nord-Lock's product portfolio and become a field of bolt safety The global leader has taken a big step forward.
Nowadays, people also emphasize analysis of joints. Eccles explained: “In the past, people were used to determining the size of fasteners based only on their own experience, and then they folded their hands together to pray for its effectiveness. Today, people pay more attention to the work of analyzing and ensuring product performance before manufacturing products and introducing them to the market. .