In mechanical processing, especially in fields such as grinding and electrical discharge machining, how to securely, stably and precisely hold those thin, small or specially-shaped magnetic conductive workpieces directly affects the processing efficiency and product quality.
Fine meshed magnetic chuck (also known as a dense magnetic suction cup) offers an outstanding solution with its extremely fine magnetic pole distribution and strong, uniform magnetic force. It has become an indispensable key fixture on equipment such as surface grinding machines and tool grinding machines.
I. Working principle of fine meshed magnetic chuck
The core appeal of the fine meshed magnetic chuck lies in its highly precise magnetic circuit design and the arrangement of magnetic poles. It uses magnetic force to adsorb conductive workpieces, but the distance between its magnetic poles is much smaller than that of ordinary suction cups.
The working principle varies according to the type:
1.Permanent magnet fine meshed magnetic chuck:
The core appeal of the fine meshed magnetic chuck lies in its highly precise magnetic circuit design and the arrangement of magnetic poles. It uses magnetic force to adsorb conductive workpieces, but the distance between its magnetic poles is much smaller than that of ordinary suction chuck.
When in the engaged state ("ON"), the magnetic lines of force start from the N pole of the magnet, penetrate the workpiece and form a closed circuit, generating a huge suction force that firmly holds the workpiece.
When in the "OFF" state, the magnetic lines form a closed loop inside the suction cup, with almost no magnetic lines escaping from the work surface. Therefore, the workpiece can be easily removed and there is almost no residual magnetism.
2.Electromagnetic fine-meshed magnetic chuck:
Its magnetic force originates from the energized coil. When the coil is energized, it generates a magnetic field, magnetizing the iron core and magnetic components inside, thereby attracting the workpiece.
The unique coil design ensures a very uniform magnetic field distribution, maximizes the suction force of the disk, and minimizes the residual magnetism.
After the power is cut off, the magnetic field disappears, but there may still be a small amount of residual magnetism.
The "fine meshed" of the fine meshed magnetic chuck is reflected in the degree of its magnetic poles' fineness. The pole strips of ordinary electromagnetic suction cups are generally 18mm iron pole + 4mm copper pole, while the pole strips of fine meshed electromagnetic suction cups can reach 1mm iron pole + 3mm copper pole, or even smaller (such as 0.5mm copper pole + 1.5mm iron pole). This dense distribution of magnetic poles enables the magnetic lines to cover the surface of the workpiece more uniformly and densely, providing sufficient and stable adhesion force for thin and small workpieces.
II. Main Characteristics and Advantages of Fine Meshed Magnetic Chuck
The fine meshed magnetic chuck combines numerous advantages, enabling it to perform exceptionally well when holding thin and small workpieces:
The magnetic field is evenly and densely distributed: The extremely fine gap distance ensures that the magnetic field distribution on the worktable is extremely uniform. This is crucial for the stable adsorption of thin and small workpieces, effectively preventing the workpieces from deforming or losing processing accuracy due to uneven force distribution.
Strong suction, low residual magnetism: Utilizing high-performance magnetic steel or optimizing the coil design, it can provide a high unit area suction force, generally ranging from 100 to 140 N/cm². A good permanent magnetic suction cup has very little remanent magnetism after demagnetization, making it easy to remove the workpiece and less likely to attract chips.
High precision and stability: The work surface has been precisely ground. The layout surface has also undergone special treatment, which not only prevents the cutting fluid from invading the interior and causing corrosion or damage, but also ensures that the accuracy of the work surface itself will not change during the demagnetization process. The thermal deformation is small, thus maintaining the processing accuracy.
High durability: If timely maintenance is provided, the fine meshed magnetic chuck will have a long service life. The specific methods for maintenance will be introduced later.
Safety and Energy Saving (Permanent Magnet Type Fine Meshed Magnetic Chuck): The fine meshed magnetic chuck does not require electrical power. It not only saves energy but also reduces the risk of losing the clamping force of the workpiece due to unexpected power outages. Therefore, the fine meshed magnetic chuck is safer and more reliable.
III. Application Scenarios
The fine meshed magnetic chuck is mainly applied in the following scenarios where high precision and stability are required:
Flat grinding machine and tool grinding machine: This is the most classic application field of fine meshed magnetic chuck. Especially for grinding thin sheet parts (such as gaskets, friction plates), small precision parts (such as small tools, precision mold parts), etc.
Electrical Discharge Machining (EDM): This process is used for attaching and positioning the workpiece and the electrode. Its uniform magnetic force and high flatness ensure the accuracy of the discharge machining.
Wire cutting machine: It is used to hold the workpiece. For some models, the fine permanent magnet suction cups can be vertically used on the wire cutting machine bed.
Jigs and fixtures: In some cases where precise positioning of magnetic workpieces is required, a fine-meshed magnetic chuck can also be used as the basic fixture.
IV. Usage and Precautions for Fine Meshed Magnetic Chuck
Proper use and maintenance can extend the lifespan of the fine-meshed magnetic chuck and ensure safe processing:
1. Basic usage steps (taking Meiwha permanent magnet fine meshed magnetic chuck as an example):
Adsorption: After cleaning the suction cup and the work surface, place the workpiece on the suction cup, ensuring that the workpiece covers as many magnetic poles as possible. Insert the wrench into the shaft hole and rotate it clockwise 180° to the "ON" position. Then, you can start the processing.
Release: After the processing is completed, rotate the wrench counterclockwise by 180 degrees to the "OFF" position, and then the workpiece can be removed.
2. Important Notes:
Maintain cleanliness: Before use, make sure to clean the surface of the suction cup and the working contact area thoroughly to avoid dust, chips, etc. from affecting the positioning accuracy and suction force.
Do not strike: It is strictly prohibited to use tools such as hammers to strike the working surface of the suction cup, as this may damage the precision ground surface and the internal magnets.
Anti-corrosion: Although most fine-meshed magnetic chucks have undergone anti-corrosion treatment, it is still recommended to clean the work surface and apply anti-rust oil for protection after the processing is completed.
Temperature control: Pay attention to the ambient temperature and avoid exceeding the specified range (typically required to be between -40°C and 50°C). Extreme temperatures may affect the magnetic properties or structure.
Workpiece material: The fine meshed magnetic chuck is only suitable for magnetic materials (such as steel, iron). For non-magnetic materials (such as aluminum, copper, austenitic 304 in stainless steel, etc.), other clamping methods are required.
Safety confirmation: For the electromagnetic suction cup, before starting the processing, it is necessary to ensure that the holding is secure; be aware that it may have residual magnetism.
V. Selection Guide for Fine Meshed Magnetic Chuck
Selecting the appropriate fine meshed magnetic chuck is the key to maximizing its performance. You can make the selection based on the following points:
1. Select based on the characteristics of the workpiece:
Size and thickness: This is the key factor in choosing the fine meshed magnetic chuck. For small and thin workpieces (typically those under 5mm in thickness), a fine meshed magnetic chuck should be selected.
Material: It must be a magnetic material. The quality of the material's magnetic property will also affect the required suction force.
Surface condition: The flatness and roughness of the workpiece surface will affect the actual contact area with the suction cup, thereby influencing the suction force. If the surface is rough or uneven, a suction cup with greater suction force should be considered.
2. Select based on processing requirements:
Cutting force magnitude: For grinding processing, a fine meshed magnetic chuck can generally be selected. If the cutting force is relatively large, a suction chuck with greater suction power is required.
Precision requirement: For high-precision processing, an air suction cup with a flat worktable surface should be selected.
3. Select the type of suction chuck:
Permanent magnet type: No electricity required, simple operation, safe and energy-efficient, with minimal residual magnetism. Suitable for most grinding and electrical processing scenarios.
Electromagnetic type: Requires power supply. The suction force can be adjusted sometimes, but there may be some residual magnetism. Be cautious of the safety of magnetic retention during power interruption.
4. Determine the specifications and dimensions:
The length and width of the suction cup should be suitable for the size of the workpiece and the size of the machine tool worktable (such as the spacing of the T-slot).
5. Pay attention to performance indicators:
Spacing and suction force: Confirm the specification of the suction cup's spacing (such as 1+3 or 0.5+1.5) and the unit area suction force (generally 100-130 N/cm²).
Accuracy grade: Focus on precision indicators such as the flatness of the work surface.
Protection performance: Verify whether it has characteristics such as preventing cutting fluid leakage and corrosion resistance.
VI. The main differences between fine-meshed magnetic chuck and ordinary suction chucks:
| Characteristic | Fine meshed magnetic chuck | Ordinary suction chuck |
| Magnetic pole separation | Extremely fine (commonly 1+3mm or 0.5+1.5mm) | Wider (such as 18+4mm) |
| Magnetic field distribution | Very uniform and dense | Relatively scattered |
| Applicable workpiece | Thin sheets, small-sized, and precision magnetic conductive workpieces | Workpieces of general size and with relatively low requirements |
| Unit suction force | Higher (typically 100 - 130 N/cm²) | Different |
| Machining precision | High | Low |
| Price | Be relatively high | Relatively low |
The fine meshed magnetic chuck effectively addresses the problems of difficult clamping, easy deformation and difficult precision control of thin, small and precision magnetic workpieces during processing, thanks to its fine magnetic poles, uniform and powerful suction force, stable accuracy and good durability.
Post time: Aug-22-2025
