Our clean-cut four-piece hole saw set cuts to a depth of 25mm. This hole saw set with precision heat-treated sharpened teeth for smooth cutting cuts a perfectly circular hole. The saw set comprises sizes 32mm, 38mm, 44mm, and 54mm. Set includes a 2.5mm hex key and one arbor. Disable your drill by unplugging it or removing the battery. Open the chuck far enough to insert the base of the arbor into the drill. Hold the saw by its base while you tighten the drill chuck, either by turning it with your hand or using a chuck key. Tighten the chuck as much as you can to prevent it from opening while you\'re using the saw. Rotate the chuck a few times by hand to make sure the saw is centred. Plugin the drill or insert the battery, and start sawing.