| All Patents in class 408/212 |
Patents 46 -
56
of 56
      |
| Number | Date | Patentee | Title | Type |
| 818,062 | Apr. 17, 1906 | S.H. Tucker | Expansible bit | adjustable drill bits |
| 832,444 | Oct. 02, 1906 | G. Arnold | Gage | drill depth stops |
| 881,856 | Mar. 10, 1908 | E. Hagstrom, G. Hagstrom, W. Hagstrom | Cup Attachment for Augers | drill accessories |
| 884,111 | Apr. 07, 1908 | O. Tack | Boring-Tool | adjustable drill bits |
| 940,426 | Nov. 16, 1909 | J.W. Caldwell | Auger-Bit | auger bits |
| 960,635 | Jun. 07, 1910 | W. Geddes | Boring or Drilling Bit | auger bits |
| 970,789 | Sep. 20, 1910 | G.P. Butler | Expansible Bit | adjustable drill bits |
| 1,056,670 | Mar. 18, 1913 | L.S. Hayden | Expansion Bit | drill bits |
| 1,140,988 | May 25, 1915 | B. Kunitz | Drill | drill bits |
| 1,379,332 | May 24, 1921 | G.P. Butler | Expansion-bit | adjustable drill bits |
| 1,727,452 | Sep. 10, 1929 | C.A. Swenson | Expansive bit | adjustable drill bits |
