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. Electrician’s Kit - 9 Pieces Comprises of 16, 20, 25, 32, 40 and 51mm variable pitch bi-metal high speed steel holesaws with hardened cutting edges, K7 Spring, K1 and K10 arbors with pilot drills. Supplied in a robust plastic carry case.