For producing high quality holes in wood, steel, brass, bronze, cast iron, aluminium and plastic. Featuring a very aggressive cutting action and M3 HSS cutting teeth to give a very smooth finish. Cuts up to 40% faster then constant pitch saws. The varying tooth pitch gives substantial reductions in noise by disrupting harmonics produced when sawing materials such as tubing, angle etc. Improved swarf clearance is also achieved requiring less effort to complete each cut. Tooth life is greatly extended, as is battery life when used with a cordless drill. Suitable for all uses: engineering, construction and maintenance. 4 to 6 teeth per inch. 28.5mm (1 1/8”) cutting depth. Tradesman’s Compact Kits High quality variable pitch bi-metal high speed steel holesaws with hardened cutting edges. Supplied in a handy storage tube. Ideal size to fit into power tool cases and tool boxes.5 Piece: Comprises of 16, 20, 25 and 30mm holesaws with K1 arbor. 11 Piece: Comprises of 16, 19, 20, 22, 25, 30, 32, 38 and 51mm holesaws with K1 and K10 arbors.