| All Patents in class 408/230 |
Patents 31 -
40
of 40
      |
| Number | Date | Patentee | Title | Type |
| 413,159 | Oct. 22, 1889 | J. Bailey | Auger | auger bits |
| 430,344 | Jun. 17, 1890 | F.I. Hoefle | Single Twist Auger Bit | auger bits |
| 451,896 | May 05, 1891 | J.E. Merritt | Twist Drill | metalworking twist drills |
| 542,223 | Jul. 02, 1895 | M.C. Johnson | Drilling Tool | drill bits |
| 597,750 | Jan. 25, 1898 | S. Smith | Bell Hangers Twist Drill | twist drill bits |
| 782,221 | Feb. 14, 1905 | P.J. Creeden | Auger-Bit | auger bits |
| 877,831 | Jan. 28, 1908 | P.J. Creedon | Auger-Bit | auger bits |
| 1,387,234 | Aug. 09, 1921 | A.J. Burke | Auger Bit | auger bits |
| 2,903,922 | Sep. 15, 1959 | W.A. Haggerty, H. Ernst | Self-Centering Drill | drill bits |
| 4,595,322 | Jun. 17, 1986 | B. Clement | Spade drill bit | drill bits |
