1. Sufficient coercivity (and therefore enough electric current) must be supplied to completely magnetize the part. This condition places a lower limit on the value of current times turns.
2. Most of the energy stored in the capacitors is converted into heat within a few milliseconds in the coil. The time is too brief for significant amounts of heat to escape to the surroundings. The coil must have enough mass that the resulting temperature rise is kept low enough to avoid overheating which could destroy the insulation. In some cases, the coil (or part of it) could even be vaporized.
3. Rejection of heat from the fixture as a whole must be high enough to allow cycling at an economical rate (if the fixture is intended for production use).
4. Eddy currents in the fixture or magnet itself must not be high enough to prevent complete and even magnetization of the part, or overheat the fixture.
5. The fixture must be strong enough mechanically to take the high forces generated by the magnetic pulse without damage. It must be constructed with enough accuracy to locate the magnet poles to within the required tolerances. It must restrain the magnet and support it well enough that the part will not be broken by the magnetic forces, and yet must not fit so tightly that thermal expansion might jam or break the part. Fast and easy loading and unloading of the part must be provided for.