The processing technology of self-locking tuning screws usually includes the following main steps:

Raw material preparation

Material selection: according to the use requirements of the self-locking tuning screw, choose the appropriate material, such as copper alloy, stainless steel, etc. These materials should have good electrical conductivity, corrosion resistance, strength and toughness.

Inspection: Strictly inspect the purchased raw materials, including the chemical composition, physical properties and surface quality of the materials, to ensure that the raw materials meet the production requirements.

Blanking: according to the design size, the raw materials are cut to the required length. Generally, sawing machine or cutting machine is used for blanking, and the blanking size should consider the allowance in the subsequent processing.

Cold upsetting forming

Die preparation: according to the shape and size of the screw, make the corresponding cold heading die. The cold heading die is usually made of high-strength alloy steel, which has high hardness and wear resistance to ensure that it can withstand great pressure during cold heading.

Cold heading processing: the raw materials after blanking are put into a cold heading machine, and the materials are extruded and shaped for many times through a die to gradually form the shapes of the head and the stem of the screw. In the process of cold heading, plastic deformation of materials occurs at room temperature, which can not only improve the density and strength of screws, but also save materials and processing time.

Thread processing

Thread rolling or thread rolling: the screw blank after cold heading needs thread processing. Common thread processing methods include thread rolling and thread rolling. Thread rolling is to put the screw blank in the middle through a pair of thread rolling plates, and make the surface of the blank form threads through the relative movement of the thread rolling plates; Thread rolling is to use two rollers with threads to place the screw blank between the rollers, and roll the threads on the surface of the blank through the rotation and extrusion of the rollers. These two methods can efficiently process high-precision threads with good surface quality and high strength.

Thread accuracy detection: After machining, it is necessary to detect the thread accuracy, including the measurement of thread diameter, pitch, profile angle and other parameters. Using thread gauge, projector and other testing equipment to ensure that the thread accuracy meets the design requirements. For the self-locking tuning screws with high precision requirements, more precise measurement and adjustment may be needed.

Self-locking structure processing

Staggered thread processing: If it is a screw that uses staggered thread to realize self-locking, it is necessary to further process the staggered tooth structure on the basis of thread processing. This usually requires the use of special tools and processing technology, and through accurate programming and control, two groups of threads staggered at a certain angle are processed on the thread surface. The angle and size of staggered teeth need to be designed and processed according to the specific self-locking requirements, so as to ensure that sufficient friction can be generated between the two groups of threads during the tightening process and realize the self-locking function.

Installation of elastic elements or molding of special structures: For screws with elastic elements to realize self-locking, elastic elements, such as spring washers and elastic snap rings, need to be installed at the corresponding parts of the screws. This requires machining suitable mounting grooves or holes on the screws, so that the elastic elements can be accurately installed and play a role. In addition, some screws may achieve self-locking through special structural design, such as setting special protrusions, grooves or deformed structures on the screw head or rod. The processing of these structures needs to adopt special molds and processes, and be shaped by stamping, extrusion or cutting.

surface treatment

Electroplating: In order to improve the corrosion resistance, conductivity and appearance quality of screws, it is usually necessary to electroplate the screws. Common electroplating processes include nickel plating, silver plating and gold plating. Electroplating can form a uniform and dense metal coating on the surface of the screw, which can not only prevent the screw from rusting and oxidation, but also improve the electrical conductivity and signal transmission performance of the screw. In the electroplating process, it is necessary to strictly control the composition, temperature, current density and other parameters of the electroplating solution to ensure the quality and thickness of the coating meet the requirements.

Electroless plating: In addition to electroplating, electroless plating is also a common surface treatment method. Electroless plating is to deposit a layer of metal or alloy coating on the surface of screws through chemical reaction, which has the advantages of uniform coating and low porosity, and is especially suitable for some screws with complex shapes and difficult electroplating. For example, for some self-locking tuning screws with special structures or blind holes, electroless plating can better achieve surface coverage and protection.

Passivation: Passivation is an important surface treatment process for self-locking tuning screws made of stainless steel. Passivation treatment can form a passivation film on the surface of stainless steel, and improve the corrosion resistance and oxidation resistance of stainless steel. By soaking the screw in the passivation solution, after a certain time and temperature treatment, the chromium on the surface of stainless steel reacts with the passivation solution to form a dense passivation film.

Precision detection and quality control

Dimensional accuracy detection: Use measuring tools such as calipers, micrometers, projectors, etc. to comprehensively detect various dimensions of screws, including diameter, length, head size, thread size, etc., to ensure that the dimensional deviation is within the tolerance range required by the design. For key dimensions, it may be necessary to use more precise measuring equipment, such as three-coordinate measuring instrument, for high-precision measurement.

Appearance quality inspection: visually or with the help of magnifying glass, microscope and other tools, check the appearance of screws to see if there are cracks, scratches, burrs, lack of materials, deformation and other defects. Appearance quality not only affects the aesthetics of screws, but also may affect their performance and assembly, so it needs to be strictly controlled.

Self-locking performance test: test the self-locking performance of the screw, simulate the tightening and loosening process in actual use, and detect the torque change and self-locking reliability of the screw. Through special torque testing equipment, the torque value of the screw under different tightening angles and strengths is measured, and whether it can be effectively self-locked without looseness is observed. For mass-produced self-locking tuning screws, sampling inspection is usually needed to ensure the consistency and stability of product quality.

Packaging and warehousing

Cleaning and drying: before packaging, clean the screws to remove impurities such as oil stain and iron filings remaining during processing, and ensure the surface of the screws to be clean. Dry after cleaning to prevent the screws from rusting during storage and transportation.

Packaging: according to the specifications, quantity and customer requirements of screws, choose the appropriate packaging method. Common packaging methods include plastic bag packaging, carton packaging and blister packaging. Attention should be paid to prevent the screws from colliding and rubbing with each other in the packaging process to avoid surface damage. At the same time, the model, specification, quantity, production date and other information of screws should be marked on the package for easy identification and management.

Warehousing: Store the packaged self-locking tuning screws in the warehouse, classify them according to varieties, specifications and batches, and do a good job in inventory management to ensure that the products are properly kept before delivery to customers.