The BlueSpot Tools 13 Piece Twist Drill Set manufactured from High-Speed Steel (HSS), is ideal for drilling in steel, iron, non-ferrous metals, plastics and wood. Contains: Sizes: 1.5, 2, 2.5, 3, 3.3, 3.5, 4, 4.2, 4.5, 5, 5.5, 6, 6.5mm. Ref: UTTK1316