Cutting depth: up to a maximum of 38 mm (1 1/2"); Ø 27 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 with HSS and variable tooth design. For easily machinable materials, the variable tooth design ensures a more uniform cut and reduced effort. The lower vibration and heat generation during cutting result in up to three times longer service life. Suitable for unalloyed steel (up to 700 N/mm² strength), non-ferrous and lightweight metals, plastics, gypsum, lightweight construction, fiber, plywood boards, and wood processing.