Drill Bits

“Three drill bits. The first the old, bad, but not yet quite superseded pattern, which is incapable of making a straight or clean hole of any considerable depth, and which loses its original diameter both in wear and in sharpening; the second the twist drill, which compares favourably with it in every one of these respects; and the third a pin drill, for enlarging a hole already existing.” —The Encyclopedia Britannica, 1903

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