The forces push away the softened or molten metal creating a cut, which further concentrates the current and forces. As a result, a runaway process can develop and a deep magnetic cut can be produced.
Magnetic sawing can be considered as the worst case of melt-wave erosion, which works in a similar way (molten metal removed by magnetic force), but over smaller volume. Magnetic sawing produces a narrower and deeper crack, which can cut through the whole thickness of the conductor.6)
Melton et al. demonstrated an experiment with aluminium bars with cross-section 44 mm x 16 mm (40 cm long) covered with thinner copper strips. A current of 1700 kA was applied for 2.1 ms or 4.39 ms. Such excitation was sufficient to create deep cuts (several mm) around the ending of the copper strip.7)
Sitzman experimented with cutting of aluminium and copper plates. The electromagnetic excitation was applied from a 13-turn coil made from copper ribbon 0.5 mm x 6.3 mm. The coil had OD 25.4 mm and ID 10.7 mm. The Al and Cu plates exposed to cutting were 0.8 mm thick, with 51 mm x 51 mm area.
The electromagnetic pulses were produced by discharging capacitors into the coil, with a specially constructed pulsed power supply. Pulses up to 80 kA could be produces, with estimated current density in the sample at the level of 105 A/mm². The pulses lasted tens of μs, and were repeated every 1 s.8)
Magnetic sawing can be used also as a useful effect, for instance for removing of unwanted metal objects.15)
In theory it can be also used for producing a cut in metal sheet. Such procedure can produce fine cuts with arbitrary length and shape, and can be referred to as non-contact magnetic cutting.16)