US Patent: 3,758,222
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Drill bit
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Patentee:
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Harry C. Oakes (exact or similar names) - Wyoming, NY |
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Patent Dates:
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Applied: |
Dec. 30, 1971 |
Granted: |
Sep. 11, 1973 |
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Jeff Joslin
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Description: |
This is the original patent for the well-known single-flute step drill for sheet metal. This simple but ingenious drill is relatively inexpensive to manufacture, combines multiple sizes in one, drills incrementally so as not to overload the drill or distort the metal, does not bind or grab, and drills a round hole cleanly and accurately. Previous step drill designs (see patents 2,897,696 and 3,564,945) have multiple flutes and greater axial clearance; Oakes' design better maintained concentricity of the stepped holes and prevented over-aggressive feeding, correcting major shortcomings of those earlier designs. As an added bonus, Oakes' bit was less expensive to manufacture. |
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