Standard_Parts_Catalogue

Page 2028 | 3.9 Holding with Magnets Application Magnets are simple elements that help make solving tasks easier, more efficient, and more reliable. If drilling is not allo- wed for fastening, for instance, so as not to damage corrosion protection layers, a retrofit/portable installation is desired, or only a temporary fix is required, this product group offers a large selection of suitable magnets. Designs There are seven different magnet types based on a conceptual classification with respect to the shape and function: Button-type magnets and U-magnets as well as retaining magnets that are disc-shaped or rod-shaped form the largest group along with screws with retaining magnet. The name retaining magnet bears such elements that are used for direct fastening. Raw magnets generally help to structure application-specific magnetic systems. Structure Apart from button-type magnets/U-magnets and raw magnets, magnetic systems can also be used. Due to their struc- ture, they have only one magnetic contact surface. Through magnetic return plates, the entire magnetic energy is con- centrated on the attracting surface and the spatial effect of the magnetic field is restricted in order to prevent any mag- netization of the environment. Materials of the magnet Within various designs, various materials of the magnet are available to choose from. In order to meet application-specific conditions in as far as possible, the most important characteristics of the respective materials of the magnet are given in the following table. Materials of the magnet in comparison Description Hard ferrite (HF) AlNiCo (AN) SmCo (SC) NdFeB (ND) Magnetic force strong medium strong very strong Max. working temperature * ≈ 200 °C ≈ 450 °C ≈ 200 °C ≈ 80 °C Magnetic force on heating lower constantly good lower lower Corrosion resistance very good very good good nickel plated - good Made from Iron oxide Aluminum, nickel, cobalt and iron Samarium and cobalt Neodymium, iron and boron Production method Sintering Sintering, casting Sintering Sintering Mechanical properties very hard, brittle very hard, tough very hard, brittle very hard, brittle Machineability not possible diamond grinding possible not possible not possible Demagnetisation capability moderate, by demagnetising fields easy, by demagnetising fields very difficult, only by large demagnetising difficult, only by large demagnetising Price very reasonable high very high reasonable * The max. temperature used is only a guide value because it also depends on the dimensions of the magnet. Retaining Magnets / Raw Magnets Application / Designs / Structure / Materials of the Magnets / Handling Instructions Handling and safety instructions The sometimes high magnetic forces of the magnets are a possible source of risk since fingers or skin can be crushed or pin- ned. Suitable protective measures, such as safety gloves, should therefore be observed in the handling of magnets to prevent injuries. It must also be noted that magnets can attract each other from great distances, depending on their strength, and also pose a risk of injuries in this way. When magnets collide forcefully, chips can be cracked off the edges or the entire magnet may break in extreme cases. Special raw magnets in an unprocessed condition can be impacted by improper handling. Magnets must never be installed in environments at risk to explosion since they can trigger sparks. Strong magnetic fields can influence or damage electrical or electronic devices. This applies to pacemakers, etc. The informa- tion from the device manufacturer regarding the specified safety distance must be observed. Disadvantageous effects of magnetic fields on the human body are not known at this time.