For optimal performance, RotoBrute annular cutters are recommended for use in RotoBrute Magnetic Drill Presses. However, standard 3/4in. Weldon Shank allows for use in most magnetic drill press systems. Plus20 XL100 High Speed Annular Cutters with Plus20 surface treatment have 20 percent more cutter life than standard annular cutters. Plus20 surface treatment also increases heat resistence for improved cutter performance. XL100 cutters are made of premium M2 high speed steel and cut fast, clean, bur free holes in steel up to 1in. depth.