Drill set 17pcs set Advanced 135°Split Point Bits Preventwalkingand provide Quick Penetration. Precision Ground from Hardened & Tempered HSS material. Titanium Coated Drill Bit Produce Higher Quality Finish Due To Reduced Friction & Heat. Titanium Drill Bits Last up to 6 Times longer. Bits Can be Resharpened. size:1mm,1mm,1.5mm,2mm,2.5mm,3mm,3.5mm,4mm,4.5mm,5mm,5.5mm,6mm,.6.5mm,7mm,7.5mm,8mm,9mm