9Pcs Tri Flat Shank Straight Flute Golden & Black Color HSS Step Drill Bit Set

for Multiple Hole Tube Sheet Drilling in Aluminum Case

1/8-1/2", 1/8-7/8", 3/16-1/2", 3/16-7/8",  1/4-3/4",

1/4-1 3/8", 7/16-1 1/8", 9/16-1", 1 3/16-1 3/8"

1. Step drill bits are perfect for drilling and enlarging multiple-holes in thin sections of sheet metals, pipes, plexiglass, plastics, wood up to a thickness of 5mm.

2. 135° Split Point Tip: increases cutting speed with self-centering and the drills do not run off center.

3. A variety of hole diameters can be drilled using only one tool. 

4. The dimension of drilled hole is exact. 

5. Two Flute Design: provides longer life and better chip removal.

6. Only for rotary use.