COBALT DRILL BIT SET. S-Tech – Get the Job Done Industrial quality for drilling stainless steel and other tough materials. Cobalt formula improves abrasive and heat resistance, for increased strength at higher drilling temperatures Surface Finish Colour – tempered finish enables identification of cobalt drills Sizes: 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13mm. GREAT FOR THE TRADES PERSON.