Laser machining has become an excellent choice for cutting thin metal substrates due to its ability to deliver
high-quality cuts with minimal material waste and fast processing times. In this research, a Nd: YAG
nanosecond laser was studied for cutting a hole of a thin electrical steel, with a thickness of 0.1 mm. The
trepanning technique was targeted for cutting a circle with a diameter of 1 mm. The three process parameters:
laser power (P), scanning speed (v), and pulse frequency (f), are examined to evaluate their influences on the
four cutting qualities of the heat affected-zone (HAZ), height of recast layer (HR), width of recast layer (WR)
and error of diameter (ED). Each process parameter is selected with three levels and a total of 27 experimental
datasets are achieved. Based on the experimental results, the preference selection index (PSI) method was used
to determine a set of process parameters through the best cutting multi-quality. Through implementing the PSI
calculation, the result shows that the best quality is found by the qualities of HAZ = 82.1 µm, HR = 17.4 µm,
WR = 24.2 µm and ED = 14 µm at process parameters of P = 9 W, v = 600 mm/s, and f = 30 kHz.