Spiral Flute Step Drill Bit,  Step Drills (Straight Flute), Step Drills Set. Such as: 3pcs Setp drills, packing with metal box, wooden box, double blister 

(1) Stright Flute / Spiral Flute
4-12mm x 9 steps
4-20mm x 9 steps 
4-30mm x 14 steps
4-32mm x 15 steps 
6-20mm x 8 steps
6-30mm x 13 steps
6-30.5mm x 10 steps
6-32mm x 9 steps
3/16"-1/2" x 6 steps
1/8"-1/2" x 13 steps
1/4"-3/4" x 9 steps
3/16"-7/8" x 12 steps
7/16"-1-1/8" x 12 steps
1/4" - 1-1/2" x 11 steps
1/2" - 1" x 9 steps
9/16" - 1" x 8 steps
3/4" - 1-3/8" x 11 steps
13/16" - 1-3/8" x 10 steps

(2) Shank: 
Round shank; 
Hex shank; 
Three flat shank; 
Hex quick change shank;

(3) Surface:
white bright;
Titanium coated;
Black nitrided;
Cobalt coated;

(4) 3pcs Step Drills Set
3/16 - 1/2 x 6 step
1/8 - 1/2 x 13 step
1/4 - 3/4 x 9 step
4 - 12mm x 9 step
4 - 20mm x 9 step
4 - 30mm x 14 step
 
4 - 12mm x 9 step
6 - 20mm x 8 step
6 - 30mm x 13 step
Packing: (a) wooden box. (b) aluminum case. (c) blister with card.

Applications:
Step Drill Bits are perfect for drilling multiple-size holes in thin sections of metal, plastic and wood using a single bit. Each step drills does the work of many drill-bit sizes. Drills round holes in most metals (steel, brass, aluminum, copper) up to 1/8" (3.2mm) thick as well as in plastic and wood. No center punching or pilot hole drilling is required on most sizes. The bits are easy to keep sharp, and the hole size is easily determined by the diameter markings that are permanently laser-etched in the flute areas.
 
Product Pictures:
 






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+86-21-20247707
+86-21-20247708
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Website: http://ostartools.en.made-in-china.com

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