Hex Titanium Step Cone Drill Bit Hole Cutter 4-22MM HSS Size: 4-22 mm（6,8,10,12,14,16,18,20, 22）mm Shank:6mm(dia),25mm(L) Total:75mm(L) Material:High speed steel Color:As shown The ladder of its structure,a bit can open a variety of specifications of aperture. Do not need to use center punch,compared with twist drill is not easy to be broken. Deburring,chamfering,elliptic hole enlargement,twist drill,the function of them was unable,but it is possible. The use of tools:drill,bench drill.Work while water cooling,can effectively extend the service life of drill bit,recommend drilling rate of 250-250 RPM. Package include 4x Hex Titanium Step Drill Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.