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Advantages and disadvantages of sheet metal joining process

1、 Welding

（1） Connection method

A processing method that achieves interatomic bonding of workpieces by heating, pressurization, or a combination of both, with or without the use of filler materials. Common methods include arc welding, resistance welding, laser welding, etc.

（2） Process advantages

（2.1）. High connection strength, able to withstand large loads and stresses, widely used in automotive manufacturing, mechanical engineering and other fields, such as welding of car bodies, ensuring the robustness and safety of the car body.

(2.2) Good sealing performance. For sheet metal structures such as containers and pipelines that require sealing, such as oil tanks and gas storage tanks, welding can effectively prevent the leakage of liquids and gases.

(2.3) It has a wide range of applications and can connect various metal materials, including carbon steel, stainless steel, aluminum alloy, etc. It is also suitable for sheet metal parts of different thicknesses and shapes.

（3） Process disadvantages

(3.1) The high temperature generated during the welding process may cause deformation of sheet metal parts, affecting their dimensional accuracy and appearance quality, especially for thin sheet metal parts, where deformation issues are more prominent.

(3.2) After welding, there may be weld marks left, which require subsequent polishing, grinding, and other treatments to improve the appearance, increasing processing costs and time.

(3.3) The welding quality is greatly affected by the technical level of the operators, and defects such as virtual welding and leakage may occur when the quality is unstable.

（4） In the manufacturing of example car bodies, welding technology is widely used to connect various sheet metal components into a whole, ensuring the strength and rigidity of the body.

2、 Riveting

（1） The method of connecting two or more sheet metal parts together using rivets is divided into solid rivet riveting, hollow rivet riveting, etc.

（2） Process advantages

(2.1) The riveting process does not require high temperature and does not produce thermal deformation, making it suitable for connecting sheet metal parts with high precision requirements, such as electronic equipment casings, precision instrument components, etc.

(2.2) Fast connection speed, high production efficiency, easy to achieve automated production, suitable for large-scale production needs.

(2.3) Riveted connection points have a certain degree of elasticity, which can absorb vibration and impact to a certain extent and improve the reliability of the structure.

（3） Process disadvantages

(3.1) Riveting parts will increase the weight of the parts, which may not be suitable for products with strict weight requirements, such as sheet metal parts in the aerospace industry.

(3.2) After riveting, rivet heads may be left on the surface, affecting the appearance, and sometimes additional treatments such as polishing and capping are required.

(3.3) The connection strength of riveting is relatively low compared to welding, and it may become loose when subjected to large tensile or shear forces.

（4） Some components of car interiors, such as dashboard frames and seat frames, are often connected using riveting technology to ensure their accuracy and reliability.

3、 Bolt connection

（1） The connection method of fixing sheet metal parts together through bolts and nuts can be divided into ordinary bolt connection and high-strength bolt connection.

（2） Process advantages

(2.1) Easy disassembly, convenient for later maintenance, replacement, and adjustment, very suitable for sheet metal structures that require frequent maintenance, such as protective covers for mechanical equipment, door panels for electrical cabinets, etc.

(2.2) The connection reliability is high, and by selecting bolt specifications and tightening torque reasonably, the strength and stability of the connection can be ensured.

(2.3) The tightness of the connection can be adjusted at any time to adapt to different working conditions and stress situations.

（3） Process disadvantages

(3.1) It is necessary to process bolt holes on sheet metal parts, which will weaken the strength of the sheet metal parts, especially stress concentration may occur around the holes, reducing the load-bearing capacity of the structure.

(3.2) Bolt connection will increase the number of parts and assembly workload, with relatively high costs, including the cost of bolts, nuts, washers and other parts, as well as the time and labor costs required for installation.

(3.3) Bolts may become loose in a vibrating environment, and anti loosening measures need to be taken, such as using anti loosening washers, locking nuts, etc.

（4） The connections between steel beams and columns in concrete building steel structures, as well as the frame structure connections of mechanical equipment, often use bolt connections for easy installation and disassembly.

4、buckle joint

（1） The connection method utilizes the interlocking structures such as slots and buckles on sheet metal parts to achieve fast connection.

（2） Process advantages

(2.1) The assembly speed is fast, without the need for additional tools and connectors, which can greatly improve production efficiency, such as the assembly of electronic product casings and the rapid assembly of furniture.

(2.2) The clamping structure has certain elasticity and buffering performance, which can absorb vibration and impact, and protect internal parts from damage.

(2.3) Disassembly is relatively convenient, reusable, conducive to product recycling and reuse, and meets environmental protection requirements.

（3） Process disadvantages

(3.1) The connection strength of the card joint is limited and not suitable for situations with large loads. It is generally used for connections in light loads or non critical parts.

(3.2) High precision is required for the processing of sheet metal parts, and the size and shape of the clamping parts must be accurately matched, otherwise it may lead to weak clamping or inability to assemble.

(3.3) After long-term use, the clamping structure may experience fatigue deformation, affecting the reliability of the connection.

（4） The shell of electronic products such as mobile phones and tablets is often assembled using a snap on structure, which is convenient and quick, as well as easy to repair and replace parts.

5、 Mortise and tenon connection

（1） Connection method

The method of processing tenons on one sheet metal part and corresponding mortise and tenon holes on another sheet metal part, and inserting tenons into the mortise and tenon holes to achieve connection.

（2） Process advantages

(2.1) The connection is firm, and the mortise and tenon structure utilizes the interlocking and fitting between parts to provide high connection strength and stability, which is suitable for some sheet metal products that require high structural strength.

(2.2) It has good decorative properties, and mortise and tenon connections can make the appearance of sheet metal parts more beautiful and exquisite. It is commonly used in the production of high-end furniture and handicrafts.

(2.3) No additional connectors are required, reducing material costs and environmental pollution.

（3） Process disadvantages

(3.1) The processing difficulty is high, requiring precise processing techniques and a high level of technical expertise. The production efficiency is low and not suitable for large-scale production.

(3.2) There are certain requirements for the material and thickness of sheet metal parts, and thinner or softer sheet metal parts may not be suitable for mortise and tenon connections.

(3.3) The structure of mortise and tenon joints is relatively complex, difficult to disassemble, and not conducive to later maintenance and replacement.

（4） The frame structure of some high-end metal furniture adopts mortise and tenon connection method, which ensures the stability of the structure and has a unique decorative effect.

6. Adhesive bonding

（1） The method of connecting sheet metal parts together using adhesive.

（2） Process advantages

(2.1) Uniform stress distribution, no stress concentration phenomenon, suitable for connecting sheet metal parts of different materials, such as metal and plastic, metal and rubber, etc.

(2.2) Good sealing performance, which can effectively prevent the leakage of liquids and gases, and also has certain insulation performance, which can be used for sealing and insulation connection of electronic devices.

(2.3) The appearance is flat, with no exposed connectors, which can improve the aesthetics of the product and is suitable for sheet metal products with high appearance requirements.

（3） Process disadvantages

(3.1) The connection strength is greatly affected by environmental factors such as temperature, humidity, chemical media, etc., which may lead to a decrease in the performance of the adhesive and a decrease in the connection strength.

(3.3) The curing time is relatively long, requiring a certain amount of time for the adhesive to fully cure, which affects production efficiency, especially for products produced on a large scale.

(3.3) The selection and use of adhesives require certain professional knowledge and skills, improper use may lead to connection failure or unstable quality.

（4） The shell and display screen frame of some electronic devices are connected using adhesive bonding technology, which not only ensures sealing performance but also has a good appearance effect.