Step drill bit
A step drill bit including a shank extending along a bit axis and a body having a proximal end adjacent the shank and a distal end opposite the proximal end. The body includes a bit tip adjacent the distal end. The bit tip includes a diameter in a direction perpendicular to the bit axis. The body defines a plurality of axially stacked, progressively sized steps including a first step adjacent and a terminal step. Each step of the plurality of steps defines a length and a diameter. The step drill bit also includes at least one flute in the body. Each flute extends from the distal end to the proximal end. The step drill bit includes a cutting edge on the flute. A ratio of the diameter of the bit tip to the length for a majority of the plurality of steps is in a range from 1.0 to 1.5.
1 . A step drill bit comprising:
a shank extending along a bit axis;
a body having a proximal end adjacent the shank and a distal end opposite the proximal end, the body including a bit tip adjacent the distal end, the bit tip including a diameter measured in a direction perpendicular to the bit axis, the body defining a plurality of axially stacked, progressively sized steps including a first step adjacent the bit tip and a terminal step at the proximal end, the plurality of steps including a plurality of stop-on steps and a plurality of intermediate steps, each step of the plurality of steps defining a length measured in a direction parallel to the bit axis and a diameter measured in a direction perpendicular to the bit axis;
a flute formed in the body, the flute extending from the distal end to the proximal end; and a cutting edge extending along the flute;
wherein a majority of the plurality of steps are intermediate steps; and
wherein a ratio of the diameter of the bit tip to the length for the majority of the plurality of steps is in a range from 1.0 to 1.5.
2 . The step drill bit of claim 1 , wherein the length of each step is not equal between the first step and the terminal step.
3 . The step drill bit of claim 1 , wherein the body has a length measured parallel to the bit axis between the distal end and the proximal end, and wherein the length is less than 4 inches.
4 . The step drill bit of claim 1 , wherein the plurality of steps includes at least 13 steps.
5 . The step drill bit of claim 1 , wherein the diameter of the tip is 0.125 inches.
6 . The step drill bit of claim 1 , wherein the length of each step is at least 0.09 inches.
7 . The step drill bit of claim 1 , wherein the terminal step defines a maximum diameter of the step drill bit.
8 . The step drill bit of claim 7 , wherein the maximum diameter is greater than 0.55 inches.
9 . The step drill bit of claim 7 , further comprising a transition portion defined between the shank and the body, the transition portion including a diameter that is smaller than the terminal step and greater than the shank.
10 . The step drill bit of claim 1 , wherein the diameters between steps incrementally increases between the first step and the terminal step.
11 . The step drill bit of claim 1 , wherein the flute extends in a direction that is generally parallel to the bit axis.