Description:3pcs HSS Step Drills Titanium Coated Quick- Change 1\/4 Inch Hex Shank 3\/16-1\/2 1\/8-1\/2 1\/4-3\/4 Inch
Introduction: Step drill，also known as multi-purpose drill with straight flute，spiral groove，single slot. White diamonds，titanium drill，colorful diamond，black diamond.Handle a round handle，triangular handle，hex shank，SDS shank. It has the functions of deburring， chamfering and elliptic hole enlargement. Don't need to use center punch， it is more durable and not easily broken compared with the ordinary twist drill.
Specification:Material: High Speed Steel 4241 ( Used for the hardness of the material which is below 25 ， like iron borad， steel board， PVC board， Insulation board， etc.)Surface: Titanium PlatedType: Straight Flute\/ Spiral GrooveHandle: Hexagon Shank 1\/4 InchScop: thin iron plate，aluminum，insulation panels，PVC panels 4mm thickness within the timber.
Size Drilling Range(!#!amp!*!Phi; inch) Hole 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

Features:High speed steel material， more durable.Titanium coated to reduce friction and run coolerNo need for a pilot hole， can automatically deburr holes as you drill.Special step stucture， can drill different size holes， 1 step drill can be used as 1 box of drill bit.Working with water cooling， can effectively extend the service life of bit， drilling speed 250--400 recommended.Widely used to cut holes in a variety of material like steel， wood， thin iron， aluminum alloy， insulation boards， PVC sheet，ect.
Package included:1x 3\/16-1\/2 Step Drill1x 1\/8-1\/2 Step Drill1x 1\/4-3\/4 Step Drill
Straight Flute:

Spiral Groove: