Permanent magnets, also known as permanent magnetic lifters in the lifting business, are lifting devices that use rare-earth permanent magnets to provide a strong holding force when handling ferromagnetic workpieces.
Their biggest advantage is their ability not to require electricity. A magnetic circuit can be engaged or disengaged by mechanical means to grip or release a workpiece. The simple structure of the tool, its safety, its energy efficiency, its low failure rate, and lack of power consumption and heat generation have all contributed to it becoming a standard in many industries, including shipbuilding, steel manufacturing, mold making, and construction machinery.
Permanent Magnet Technical Data
The following parameters are important to consider when buying or using any equipment:
a. Rated Lifting capacity: The maximum weight that equipment can safely raise; specifications typically range from 100kg to 10,000kg.
Breakaway Force: This is the force that must be applied to the magnet in order for it to release the workpiece. It is an important safety indicator and should typically be 3-4 times higher than the rated capacity of the lifter (e.g., 2.8x, 3,5x).
Safety Factor: The relationship between the breakaway force and the rated lifting capability. Safety factors can reach 3 or even 3.5 for permanent magnet lifters that are operated manually.
d. Operating temperature: To maintain a magnetic force that is stable, both the ambient temperature and the temperature of the workpiece must generally not exceed 80degC.
Workpieces that are suitable: These include steel plates, steel profiles, and mechanical parts.
Dead Weight: This refers to the weight of an item. This can vary greatly depending on its model and specification. It may range anywhere from a few kgs to hundreds.
Permanent Magnet Chuck Information
Structure
The manual permanent lifter is a straightforward device, with only two main parts: the housing of the lifter and the magnetic shaft.
Housing: Made up of multiple ferromagnetic elements, the housing is the main structural component of the device.
Magnetic Shaft (also known as the Shaft of Magnets): The core component for controlling the magnetic circuit, it is embedded with permanent magnets.
V Groove: At the bottom, the device features a V groove which allows it to grip cylinders such as round bar steel and steel pipes.
Features
No electricity is required. Magnetism remains in place even when power fails.
Simple operation. Release and engagement can be achieved with only one hand.
The power supply is virtually maintenance-free and requires little to no weight.
The V-grooved Base allows lifting both flat steel sheets and round steel stocks;
Avoid damaging the surface of workpieces.
Application
For mold workshops, steel structure plants, machinery, and shipyards. Used for lifting ferromagnetic objects such as thick sheets of steel, forgings, moulds, round steel bar, and steel pipe. Compatible with Magnetic overhead cranes, gantry cranes, and small hoisting devices.
Use of the Permanent Magnetic Lifter
Workpiece Conditions
Suitable only for lifting low-alloy steels and carbon steels. Use of stainless steel austenitic, aluminum, or Copper is strictly prohibited.
The workpiece's surface should be flat and as clean as possible. Paint, mill scale, and oil will create air pockets that reduce the lifting force.
The workpiece thickness should meet the equipment's specification. Too thin sheets could cause the underlying material to lift along with the target, causing a detachment.
Make sure the workpiece is in full contact with the base’s surface.
Operational Guidelines
Work within the maximum load as specified on the label. Overloading is not permitted, nor are angular dragging, angular yanking, or angular squatting.
The handle should be rotated fully to its "OFF" position after the workpiece is lowered. Verify the workpiece is fully detached and then move the lifter.
Standing underneath the suspended loads during lifting is strictly prohibited.
The maximum temperature for the ambient air is 80 degrees Celsius. Don't drop the unit or expose it to open flames.
A spreader beam is required to distribute the load evenly when multiple units are used for a combined lift. Rated capacities cannot simply be multiplied together.
Operating conditions that are prohibited
Never lift molten metal or workpieces at high temperatures.
Never lift iron filings, non-magnetic metals, or loose scrap.
Avoid using the device in situations where there is a high level of vibration or severe impact.
Keep magnets away from strong magnetic fields to prevent demagnetization.
Maintenance and Care
The equipment will last longer if you maintain it properly.
Cleaning and Rust Prevention: After each usage, clean the magnetic chuck's working surface and apply anti-rust oils to prevent corrosion.
Avoid Impact. To prevent magnetic force reduction or damage to internal circuitry, avoid hitting or bumping the surface of the magnetic chuck.
Proper Storage - When not in operation, turn the handle "OFF". Store the equipment in an area that is dry and level.
Maintenance and Scrapping
Regularly check for cracks, deformations, smoothness of the handle, and impact damage on the surface.
If there is any surface damage, such as a dent or handle jamming, or the magnetic force drops dramatically, immediately discontinue using this product.
Store in a cool and dry place. Do NOT leave the device attached for an extended period of time to a metal plate.
The unit should be disposed of immediately if there is any damage to the internal mechanisms or magnetization. Do not attempt to repair this device for further use.
How to Choose the Best Permanent Magnet Lifter?
Follow these steps when selecting the appropriate permanent magnet lifter.
1. The weight of the workpiece is the most important factor to consider when selecting a lifter. Calculate the weight of the heavy workpiece you will be lifting and choose the model that matches the rating.
2. Think about the shape of the workpiece: Standard models work well for iron blocks and steel plates; models with "V" grooves at the base work better for cylindrical workpieces, like steel tubes or round bars.
3. Assess the operating conditions: Make sure that the ambient temperature is within the acceptable range of the machine (normally = 80 °C). Also, ensure that the workpiece is as flat as possible and free of contaminants.
4. Combination of lifters: When lifting large workpieces with a long surface area, it is possible to use multiple permanent magnet lifters together to evenly distribute the load.
Finally Words
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