What Is A Cold Pier Screw?

Screw cold block refers to the process of cold block screws, also known as cold extrusion, in which the metal is squeezed to the material at room temperature to produce certain plastic deformation and turn it into the desired shape in the design drawing. There are many screw materials that can be used for cold pier, and common carbon steel, medium carbon steel and stainless steel can be produced. Cold pier screws are the most practical way to manufacture screws at present because of their fast production speed and no waste.

Cold pier equipment is now mainly based on multi tapping machine, which can cut materials, shape heads, chamfer and rub teeth in order. Ordinary small screws can produce more than 300 screws per minute, which is very efficient. The heads of the common outer hexagon screws and inner hexagon screws are formed and produced in this way at one time, but some preparatory work needs to be done before the screws are cold rolled.

The first is the annealing of wire rods. If you do not anneal, you will be worried that the strength of the equipment is not big enough, and it is very difficult to form. Therefore, the purpose of annealing is to make the hardness of the material lower, and it is easy to produce when the mold is hit. The material is annealed in a constant temperature furnace, which should be kept for three to four hours, and then can be cleaned after natural cooling.

In fact, the purpose of material cleaning is not to make it clean. Strictly speaking, it is a kind of acid cleaning. Use some chemical solution to remove the surface oxide layer of the material, so that the material can be more lubricated. In this way, it is very convenient to pull the material into the wire diameter requirements for screw production. Only after these processes can we get to the production line for final cold pier forming.

If it is a standard screw, it is OK to install the corresponding mold for production. If it is a cold pier non-standard screw, it is necessary to first produce the mold according to the drawing, install the mold, test several products, and then check its size. After it is completely correct, it can be mass produced.

For the conventional hex cap screws, the four die equipment is used to complete the production at one time. First, the material is broken. According to the length of the screw, the material is cut off. Then the die stamping turns the material into the blank of the screw. Finally, the trimming process is performed to form a blank screw before the thread rolling. Finally, as long as the screw is placed in the thread rolling machine, the final forming process can be completed. And the cleaning and surface treatment is a natural thing.

How did the nut come out? The processing of materials is the same as that of screws. When the line materials are processed, take the production line and cut off the materials first. The first mold movement will shape the appearance of the nut, and the second mold pressing movement will shape the inner hole of the nut, and then the line tapping production line will complete the final tapping.

The forming of screws and nuts is relatively easy. The quality of a screw is not only the process of cold pier forming, but also the heat treatment of the finished product. The heat treatment shall be carried out according to the different materials of the screws. In general, it is first high temperature quenching, then medium temperature heating, and finally low temperature carburizing.

When everything is ready, the surface of the screw is treated. The surface coating is treated according to the actual requirements. This is what follows. We have detailed some knowledge and information about the surface treatment of the screw in other articles. If necessary, you can refer to it yourself. It will not be repeated here.

The corresponding screw cold forging process is hot forging, which can also be called red forging. Red forging screws are some super large screws. Cold forging equipment can not be produced, so red forging screws can only be used as a last resort. To put it simply, red forging screws burn the materials red first and then become soft, and then use a simple stamping die to shape the red forging materials. The production speed of red screw is slow, and the precision is not high. If it is not absolutely necessary, do not choose the red screw process.

      There are two common materials for cold pier screws, one is carbon steel cold pier screws, and the other is stainless steel cold pier screws. It is widely used in electronic, electrical, mechanical equipment and various major industries of aviation communication. As one of the basic fastener industries in China, cold block screws have fully realized automatic production, improved efficiency and reduced product prices, which is the biggest advantage of cold block screws. Cold pier screws have been in line with international standards for nearly 20 years, and the manufacturing technology of cold pier screws has been greatly improved. From the earliest second tapping machine to the current all-around cold pier machine, the space that was originally supplemented by red screws due to the lack of technology has been replaced by the improvement of cold pier screw technology. No matter how hard the material is, it can be used to produce screws by cold pier only if it has certain plastic deformation.

Cold pier screw is a process of directly deforming materials with molds or other methods under normal temperature environment according to the deformation coefficient of metal materials. If the plasticity of materials is high, the requirements for equipment will be lower. On the contrary, if the hardness of materials is high and the plasticity is low, the requirements for equipment of cold pier screw will be higher.

The existing cold pier screw equipment will match the performance of the equipment according to the screws and nuts of different specifications, so that professional equipment can drive professional screws. The screws produced have good finish and higher dimensional tolerance accuracy, and these advantages are not up to the standard of hot tapping screws. For hot screwing, the material must be annealed first, and then burned red at high temperature to make the plasticity better, and then the die is used to extrude the screw. Although the production method of hot screwing is simple, after the material is burned soft at high temperature, it has a great impact on the surface smoothness. After the production is completed, another process of burr treatment is required, which also adds some costs to the screw. Moreover, the production speed of this kind of hot screws is very slow, and it takes a process for materials to be heated in the high-frequency furnace, which leads to insufficient shipment of hot screws.

As for the cold pier screws, basically all the materials used for the production of fasteners can be formed at one time. As long as the mold meets the requirements, according to different specifications, after the installation and commissioning of equipment, it is unnecessary to send the line materials to the transmission line. The cost is low and the speed is fast. The size standard is 98% of the screws are cold pier screws.

For Jinrui, whether you are a fastener demander/dealer/supplier, you can visit the official website of Jinrui for more information:https://www.jinruibolt.com/

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Jiangsu Jinrui Metal Products Co., Ltd. is the production base of Shanghai Jinrui standard parts. The factory covers an area of more than 20000 square meters, with a registered capital of 50 million yuan, a total investment of more than 100 million yuan, and an annual output of more than 20000 tons. Its products are exported to more than 40 countries.

Since its establishment in 2001, Jinrui Company has developed into a new layout with Hai'an in Jiangsu as its production base and Baoshan in Shanghai and Nanyang in Henan as its sales centers after more than 20 years of unremitting efforts.

At present, Jinrui's main products include the following six categories:

1. The main products of bolts include metric and American round head oval neck bolts (also called fishtail bolts), internal and external hexagon bolts, hexagon flange bolts, carriage bolts, wheel hub bolts, etc

2. Stud products: full thread thread, double head studs, etc

3. Nut products: hexagon nut, flange nut, heavy nut, square nut, butterfly nut, etc

4. Screw products: self tapping screws, self tapping self drilling screws, wood screws, various machine screws, etc

5. Washer products: flat washer, spring washer, square washer, lock washer, etc

6. Fastener related non-standard products

The wire drawing plant under Jinrui Company also provides processing services such as fine drawing, rough drawing and spheroidizing of wire rods, and supplies finished wire rods of various domestic famous steel mills.

Adhering to the business philosophy of "pioneering and innovation, pursuing excellence", Jinrui has successively introduced multiple types of heading and forming machines, thread rolling machines, nut machines, hot heading and rolling machines, lathes, large hot heading machines and their supporting testing equipment, such as magnetic particle flaw detectors, metallographic analyzers, salt spray testing machines, direct reading spectrometers and optical screening machines, tensile machines, Vickers hardness meters, Rockwell hardness meters, etc., and has set up independent research and development departments, It can produce all kinds of high-quality fasteners such as GB, DIN, ANSI, JIS and ISO international standards. The products are widely used in petroleum, chemical industry, boiler, wind power generation, highway guardrail board, elevator guide rail, machinery manufacturing, construction sites, auto parts, medical equipment and other fields.

Jinrui has been developing vigorously since its establishment. It integrates the advantages of each company, carefully designs and strictly selects materials to make the products more durable, and is highly praised by the majority of users. Jinrui won the ISO9001: 2000 international quality system certification in 2001, the special equipment manufacturing license in 2010, and the TS16949 automobile quality management system certification in 2012. The People's Insurance Company of China underwrites the "Global Product Liability Insurance" for its products, ensuring that every screw can be used with confidence, determination, and peace of mind!

Whether now or in the future, Jinrui will always adhere to the core service concept of "quality first, science and technology to revitalize enterprises, users first, and considerate service", sincerely provide you with high-quality services and high-quality products, and Jinrui will also become your most loyal long-term partner.