The Starrett Deep Cut Bi Metal Holesaws combine the tried and tested tooth form used on the previous Dual Pitch Holesaw, with a new tooth material for enhanced heat and wear resistance. The Deep Cut saw also features an increased hole saw depth of 51mm (2in), and is ideal for cutting metal of more than 3mm thickness, tubes with a wall thickness of greater than 3mm and wood up to 51mm (2in) thick. Cutting Depth: 51mm.Starrett DCH2532 Deep Cut Bi Metal Holesaw has the following specification: Diameter: 20mm (25/32in).