The planet earth is full of different types of permanent magnets. These are made of different alloys and are of different shapes, sizes, and designs. These also possess different magnetic strength.
The magnetic strength varies along with the proportion, quantity and quality of the different metallic alloys which are mixed for making the magnets. There are some commonly used shapes and designs of the permanent magnets, which are-
Bar magnets.
Cylindrical solid magnet.
Cylindrical magnets with holes.
Ring magnets.
Rectangular magnets with holes and without holes.
Chuck magnets.
Arc or Crescent magnents.
U-shaped magnents.
Horse-shoe magnets.
Square magnets with holes or without holes.
Cup shape covered magnets.
The sizes of these magnets differ as per the requirements and the purposes for which they are made. The above shapes of magnets are generally produced by the manufacturing companies. The permanent magnets are made with the alloys already in use, according to any given measurements or specifications to suit any purpose, in any shape, size, design or strength.
The permanent magnets are generally of low strength and are mainly made for industrial, commercial and educational purposes but some of them are also utilised for medical purposes.