Cutting depth: up to a maximum of 38 mm (1 1/2"); Ø 51 mm. The RUKO bi-metal hole saws can be used in hand and pillar drilling machines. For pillar drilling machines, please use manual feed only. Bi-metal hole saws HSS with variable tooth design. For easily machinable materials, the variable tooth design provides a more even cut and requires less effort. The reduced vibration and heat generation during cutting results in up to three times longer tool life. Suitable for unalloyed steel (up to 700 N/mm² strength), non-ferrous and light metals, plastics, gypsum, lightweight construction, fiber, plywood panels, and wood processing.