subject: The Various Forms of Disc Magnets and Their Applications [print this page] In recent years, the use of disc magnets in the commercial world has increased. Neodymium disc-shaped magnets have been phased in to replace magnet types such as alnico and ferrite magnets, as neodymium magnets are small yet very powerful. For example, the growing trend for manufacturers to make much more powerful computer speakers and hard drives has led to the increased uptake of neodymium magnets, as the manufacturers require very small magnets to fit inside small electronic parts. For example, in many hard drives, the thin plate opposite the read-write disks contains a small neodymium magnet. In addition, another neodymium disc magnet lies below the plate inside an actuator. Although the majority of the newer hard drives on the market contain two magnets, a minority contain just one, rendering them less powerful than their dual-magnet counterparts. The power of neodymium magnets when compared with alnico magnets may be demonstrated in this context - an alnico magnet ten times the equivalent size of a neodymium magnet must be used to achieve the same force inside the hard drive. This goes to show that neodymium magnets are much stronger than their alnico equivalents!
The Various Forms of Disc Magnets and Their Applications