The holding magnets are of different shape,such as square, disc and cylinder. Hard ferrite, alnico,NdFeB and SmCo assemblyies are specified for many applications in all industries and engineering. These magnets are made by setting different magnets into steel housing with some magnetic insulate material,such as brass and aluminum. The holding magnet has a particular magnetic circuit which can concentrate or insulate magnetic power at a target space around the assembly. The holding magnets can be coated in white,black,gray,nickel or zinc plating, or even rubber cover.