| All Patents in class 408/212 |
Patents 16 -
30
of 56
      |
| Number | Date | Patentee | Title | Type |
| 166,221 | Aug. 03, 1875 | T.D. Parsons | Improvement in Augers | auger bits |
| 169,075 | Oct. 26, 1875 | A.B. Batson | Improvement in Bit-Gages | drill depth stops |
| 198,857 | Jan. 01, 1878 | H.L. Shaler | Improvement in Augers | auger bits |
| 235,234 | Dec. 07, 1880 | R.E. Hardisty | Auger | auger bits |
| 242,362 | May 31, 1881 | W.L. Parmelee | Auger | auger bits |
| 269,406 | Dec. 19, 1882 | P.A. Gladwin | Auger | adjustable drill bits |
| 279,204 | Jun. 12, 1883 | J. Swan | Adjustable Auger | adjustable drill bits |
| 287,538 | Oct. 30, 1883 | E. Hall | Threaded Spur Auger Bit | auger bits |
| 289,126 | Nov. 27, 1883 | G. Nichols | Expansion-Bit | adjustable drill bits |
| 302,595 | Jul. 29, 1884 | H.L. Shaler | Auger Bit | auger bits |
| 313,735 | Mar. 10, 1885 | G.H. Hill | Expansible bit | adjustable drill bits |
| 360,990 | Apr. 12, 1887 | C.E. Billings | Expansive bit | adjustable drill bits |
| 404,197 | May 28, 1889 | C.H. Irwin | Auger-Bit | auger bits |
| 413,159 | Oct. 22, 1889 | J. Bailey | Auger | auger bits |
| 413,972 | Oct. 29, 1889 | H.L. Shaler | Auger | auger bits |
