Description:3pcs HSS 1\/4 Inch Hex Shank Titanium Coated Step Cone Drill Bit Set in Pouch<br>Specification:Surface: Titanium CoatedType: Straight Flute\/ Spiral GrooveHandle: 1\/4 Inch Hexagon ShankMaterial:  High Speed Steel ( Used for the hardness of the material which is below 25 ， like iron borad， steel board， PVC board， Insulation board， etc.)<br>          Size    (Inch)       Drilling Range(&amp;Phi; inch)       Hole    (mm)       Height(mm)    {Straight Flute}       Height(mm)    {Spiral Groove}       Height of Shank (MM)       Shank Diameter(&amp;Phi; inch)           3\/16-1\/2       3\/16，1\/4，5\/16，3\/8，7\/16，1\/2       6       88       87       24       1\/4           1\/8-1\/2       1\/8，5\/32，7\/32，1\/4，9\/32，5\/16，11\/32，3\/8，13\/32，7\/16，15\/32，1\/2       12       75       75           1\/4-3\/4       1\/4，5\/16，3\/8，7\/16，1\/2，9\/16，5\/8，11\/16，3\/4       9       73       72   <br>Features: Products for automotive processing， aerospace， sheet metal processing， installation and maintenance of electrical and other industries， high-altitude operations with hand drills and other tools.Usable Scop: thin iron plate，aluminum，insulation panels，PVC panels 4mm thickness within the timber.<br>Package Included:1 x Set (3pcs) Step Drill Bit in Pouch<br>More Deatils: