Lifting magnets are very instrumentals in a number of factories that require material and work pieces to be lifted from one place to another. There is quite a number of lifting magnets but the two wide categories are permanent lifting magnets and electromagnet. Both these categories have their advantages as well as disadvantages and these go a long way in helping one decide which type of permanent magnet he/ she will procure.
Advantages of permanent lifting magnets over electromagnets
The major advantage of permanent lifting magnets is the fact that they do not require electric power to make them magnetic and therefore they can operate just fine in areas where electric power is not available or when power fails. This makes permanent lifting magnets relatively cheaper than equivalent electromagnet as they have minimum if any maintenance cost.
Another advantage is that they are usually designed with wide or long surfaces and as such provide a wider area for magnetic coverage. This coupled with its constant magnetic strength makes permanent magnets perfected for lifting materials of varied sizes and shapes.
Where work parts have to be lifted very high, permanent magnets have superior functionality than electromagnets as they are far much lighter than the later. This characteristic also makes them far much safer than electromagnets in such scenarios as the risk of them dropping the item is minimized.
Electrical contact in electromagnets may cause problems that eventually deteriorate the magnets. This is not the case with permanent lifting magnets. These magnets also do not cause damages to test pieces as seen in electromagnets.
Disadvantages of Permanent lifting magnets
These magnets are very durable but they are disadvantaged in that they deteriorate with wear. When this happen, they will lose their magnetism and thus become a danger to work with. This will necessitate replacement which a costly process. The fact that permanent magnets retain their magnetism could be a pro as well as a con. Its downside is witnessed when the target load has been lifted and magnet has to be literally pulled off the item. In electromagnet, this tedious process is not necessary as all you simply need to do is to turn the switch off and once the current stops flowing in the insulated wire coil, it loses its magnetism and the item is immediately released.
Another major disadvantages of permanent lifting magnet compared to electromagnet is the fact that you have absolutely no control over field strength. Changing magnetic field to suit the item that you want to work on is however possible in electromagnets. This is done by simply controlling the current that flows through the coil of wire rapped across the core of the ferromagnetic material.
Permanent magnets are sensitive to air spaces and they function better where there are no air spaces between it and the item being lifted. However, these magnets tend to attract unwanted ferromagnetic metals and other materialist the poles and therefore creates spaces that may reduce lifting capacity of the magnet. These items have to be pulled out for the magnet to lift a load and this is tedious.