Pot magnets consists of magnet material enclosed in a metal 'pot', The active magnet face is not enclosed
. The pot is an essential part of the magnetic circuit. The two magnetic poles are concentric and are both on the end face of the magnet. Pot magnets are the most efficient design for gripping (other designs are preferable for lifting and attracting across air gaps). Features:
- No stray flux as magnetism is retained in a closed circuit
- The pot screens the magnet material from de-magnetising effects
- Pot is machineable
- Can be inserted into, fitted to, steel without adverse effect (cannot be done with unscreened magnets)
- Magnet proper is most efficient magnet shape (plain cylinder magnetised lengthways)
- Concentration of flux in the mild steel possibly twice that of the magnet proper, creating increased gripping power
- Distance of magnetic attraction lower than that of other magnets but grip in intimate contact is vastly superior to magnets of similar material and weight but different design.
Which magnetic handling product is the right one for your application? 
Company literature available as PDFs including the Product Catalogue, Micromag and Ultralift+
