Regardless of the drill diameter, since the size of the chuck part will be the same, I bought it. Acrylic is easy to break, so it is necessary to increase the diameter little by little when drilling work. That is, I frequently exchange the drill, but it was troublesome to adjust the chuck each time. With this drill, all diameters are the same, making exchange very easy. The discontinuities are originally for metal and outstanding sharpness. Still, if you apply more force than necessary, acrylic will crack, so moderate.