Handy portable case. Starrett 7 Piece Deep Cut Bi-Metal Hole-saw Kit. Features and Benefits. 7 piece deep cut bi-metal hole-saw Kit Hole-saw Diameters: 20 mm, 25 mm, 32 mm, 40 mm, 51 mm Arbors: A1E (14 mm to 30 mm), A2E (32 mm to 210 mm) 51 mm hole saw depth improves cutting performance on tubes, particularly where there is a need to cut through both sides New tooth material with extra cobalt for enhanced heat and wear resistance - improving the product life Ideal for solid materials greater than 3 mm in thickness. Aggressive material penetration and kerf clearance. Application Information. Ideal for woodwork, workshops and construction applications