In the early days of the fastener industry, the "factory" formed by the merger of several small blacksmith workshops was actually a larger workshop. The main products are all kinds of bolts, nuts and forged small pieces. More than the sample production, there is basically no product drawings, there is no paper surface process, it is not known what "standard", "standard parts". The blanks of bolts and nuts are made of hot forging, and the simple mechanical press and hand hammer for hammer and hammer are used together. All products are heated in a coal stove. After forging, the products that oxidize the skin are not removed. They are called "bristles" and "hair nuts". It is necessary to remove the scale (which is already required in the market), and a process called "lighting" (the forged blank is pickled and cold extruded through a hexagonal die hole) can remove the oxidation of the hexagonal surface and squeeze it smoothly. In the early and middle of the 1960s, some professional factories in Shanghai have adopted this process in large quantities. From the perspectives of process flow, technical proverbs, tool structure, etc., the process technology adopted in Wuhan originates from the possibility of Shanghai. Big). The oxide rod and the flash of the bolt stem and the nut end face can only be removed by cutting. The bolt that requires the whole body to "cut light" is mainly a hexagonal screw called "head screw". The thread is made of Imperial "Wyeth" (also known as "Wyeth"), which is the oldest thread standard in the UK, but the factory At that time, there was no such standard, but it was only "in accordance with the actual product". The root and tip of the thread required a circular arc shape, and the hand must be smooth. It is extremely difficult to see the threaded bolt. . This is a legacy of the old era using a large number of imperial machinery, which was still in heavy use due to maintenance and habits. Even the packaging uses the old rules, the counting theory "hits", each "hit" 12 pieces, every 12 "hits" is a "ro", carton packaging, generally one box per box. Although the "head screw" has no dimensional accuracy, it has a fairly strict appearance requirement. The hexagonal surface must be smooth, and there must be no visible spots or rust on the naked eye. The thread must be full and there must be no missing teeth. ,glitch. To this end, this product is 100% manual picking. The market demand at that time had profoundly affected the operation of these small businesses. Its main sales direction is the hardware store, which was slowly reduced until its death in 1960.
Hot pressing and manual hot forging are the basic way to shape the product. The special size is that the diameter is large or the rod is extra long, the batch size is small, the manual is used, the batch size is slightly larger, and the medium size is used, and the machine tool is used for enthusiasm. Molding molds are manufactured in the simplest way. Cars, planers and fitters are hand-finished. Grinding machines are not available. Even sanding and oil sanding are “finishingâ€. The heat treatment of the mold is also done with a coal stove, which is mastered by the master “seeing the color†(the temperature of the heating and the color of the temper), which may be the technology that has been used for thousands of years. The steel for hot forging core is mainly made of domestic high-carbon tool steel at that time. (In the 1950s, China's basic steel system was established. The steel grade of high-carbon tool steel is “ㄊ8,ã„Š10â€, “ㄊ "It is the old Chinese phonetic symbol, which corresponds to the "T" of the Chinese pinyin, that is, the later T8, T10. The master who does not have much literacy refers to this steel as "Cloud 8" and "Cloud 10" steel). Regardless of the steel used in the product or tooling, what the material store says is the steel number, even if the steel number is neither the concept of "acceptance" nor the condition.
Machine tools for product cutting are almost always simple and special machines, and are generally "belt machines" without motors. A type of machine called the "Tian axis" is the most common. Under the truss of 2-3 meters above the ground, a "million axis" of several meters long is traversed by a motor. A number of pulleys are mounted on the "Tian axis", each of which is connected to the pulley of each small machine on the ground with a long flat belt. When the “Tian axis†is activated, all the machine tools can work (each machine has its own device that can control the opening and closing). Once such a workshop starts, dozens of belts hunted and flew up and down, and the spectacular is also thrilling. Safety issues are naturally inevitable, but it seems that the factory or superiors are used to it, but they ask. Even if you only need to open a machine, you have to. It seems that this is really hard to imagine. Car bolt heads, cars (strictly regarded as "milling") nut end faces, car bolt stems or rod ends, "sleeve" threads, etc., are almost all such special machine tools, they already have "specialization" "The basic characteristics." The structure is basically the same, small and simple, but the head and the fixture are different. However, they are extremely easy to imitate, and they are undoubtedly made in the industry. Until the 1990s, in Jiangsu and Zhejiang provinces, a large number of similar special-purpose machine tools that were made by professional companies for their own use or supplied to other factories were widely used. Simple and special, this can be considered as an inevitable process or way of professional development of fasteners.
The most important element of the bolt, the thread, is to use the "square die thread", which is a technology that is now basically extinct. The degree of surface smoothness of the thread is controlled by the skill of the master to manually grind the die. When I first entered the factory to participate in labor, I had done the work of “threadingâ€. The “cutting theory†that I learned in school should be applied to the grinding of the dies, which is really difficult, because this “soil die†is almost in the textbook. Did not mention, let alone control by hand, it is easy! Although the thread of the nut is also tapped by the "tose", there is no "precision" concept. The tapped nut can be bolted and it is "ok". The material used for the product is “ㄤ(音ang)3†(the steel number specified by the old Chinese phonetic symbols in the 1950s, that is, the later carbon steel A3), which naturally does not matter. Whether it is "hair products" or "light products", it is also not treated with surface treatment.
Interestingly, where do these technologies with specialized nature come from? According to observations of similar enterprises in various places, general inference can be obtained, and the source should be coastal cities such as Shanghai. The first large-scale inflow to the interior was during the anti-Japanese period (the bosses and masters of the factory where the author is located are the Jiangsu and Zhejiang people who are called "Xiajiang people"). When some of the companies that moved in are local, their technology will be immediately It will inevitably gradually spread outward. Moreover, it is conceivable that the technology that landed in a certain place will inevitably have different degrees of improvement in its application process. This is roughly the vein of the technological development of a large number of small fastener enterprises in the period of professional germination from the 1940s to the 1950s. At that time, there was a concept of making screws and nuts in Shanghai. In the late 1950s, this factory organized a team of 7 or 8 people to go to Shanghai to "take the classics". This is the first time the factory went to Shanghai to seek art (there have been many times in the following years, this is a later words). This shows that Shanghai is indeed one of the sources of domestic fastener technology.
When I entered the factory, the strongest feeling for the author was: "Isn't this a complete workshop?" I can't help but sigh, the "Su-style theory" taught by the schools (the school used a full set of former Soviet textbooks, directly after translation Use, both theory and practice, the students who have passed this formal education have indeed benefited a lot and benefited from life. Compared with the actual state of technology, the gap is so great. How can it come in handy? Of course, subsequent developments show that this concern is only temporary. Assigning class students to these small businesses actually injects vital and even critical technical factors into their future development and upgrading. It is really a very discerning decision.
In the "blacksmith workshop", the state of domestic fastener companies was probably the same. It is the innumerable small fastener factory that meets the needs of the “small screws†needed for the restoration and construction of the new China (the first bridge of the Yangtze River – the tens of thousands of large rivets required for the Wuhan Yangtze River Bridge) It is provided by the small factory in Wuhan, using the original technology and equipment, and using the sweat of the employees as scheduled.) The "workshop" of the year was like a virgin land to be reclaimed. The fastener industry in China will only grow and develop on this land in the future.
Soon after, these workshop-style small fastener factories in China will usher in an unexpected spring of leapfrog development.
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