| All Patents in class 451/274 |
Patents 1 -
10
of 12
      |
| Picture | Number | Date | Patentee | Title |
| | 832,380 | Oct. 02, 1906 | J. Hartness | Tap and Process of Making the Same |
| | 1,835,476 | Dec. 08, 1931 | J.C. Drader | Grinding Fixture |
| | 1,918,951 | Jul. 18, 1933 | C.J. Anderson | Grinding machine |
 | 2,035,163 | Mar. 24, 1936 | K.W. Holmberg | Tool Holder and Guide |
 | 2,147,227 | Feb. 14, 1939 | G.B. Ambler | Drill sharpening machine |
| | 2,429,250 | Oct. 21, 1947 | C.A. Wiken, E.A. Reibig | Grinding machine |
| | 2,480,285 | Aug. 30, 1949 | E.J. Bullard | Lapping Machine |
 | 2,617,237 | Nov. 11, 1952 | E.P. Sacrey | Cutter head sharpening attachment |
| | 2,754,634 | Jul. 17, 1956 | W.F. French | Tooth rests for cutter grinders |
| | 2,787,094 | Apr. 02, 1957 | W.F. French | Cutter grinders |
