| All Patents in class 408/230 |
Patents 16 -
30
of 40
      |
| Number | Date | Patentee | Title | Type |
| 95,803 | Oct. 12, 1869 | W.A. Ives | Improvement in Auger | auger bits |
| 97,818 | Dec. 14, 1869 | S. Scholfield | Improvement in Twist-Drills | twist drill bits |
| 112,115 | Feb. 28, 1871 | T.V. Boyden | Twist Drill Bit | twist drill bits |
| 115,541 | May 30, 1871 | J. Swan | Improvement in Augers | auger bits |
| 118,178 | Aug. 22, 1871 | B. Arnold | Improvement in Twist-Drills | twist drill bits |
| 151,450 | May 26, 1874 | C.C. Tolman | Improvement in Boring Bits | |
| 164,999 | Jun. 29, 1875 | G.L. Holt | Twist Drill for Wood | twist drill bits |
| 245,106 | Aug. 02, 1881 | M.S. Weller | Tapered Twist Drill Bit | twist drill bits |
| 248,854 | Nov. 01, 1881 | P.A. Gladwin | Auger Bit with Cross-Channel Lead Screw | auger bits |
| 258,390 | May 23, 1882 | G.W. Dudley | Reamer | tapered reamers |
| 260,314 | Jun. 27, 1882 | G.V. Sheffield, J.A. Parks | Drill Chuck | drill press chucks |
| 270,258 | Jan. 09, 1883 | J.H. Stickney | Brad-awl | gimlets |
| 270,366 | Jan. 09, 1883 | W.H. Thorne, J.S. Bancroft | Drill | drill sharpening machines |
| 305,625 | Sep. 23, 1884 | T. Newey, Jr. | Auger Bit Without Gimlet Lead | auger bits |
| 364,153 | May 31, 1887 | C. Whitehouse | Auger Bit | auger bits |
