| All Patents in class 451/274 |
Patents 1 -
12
of 12
      |
| Number | Date | Patentee | Title | Type |
| 832,380 | Oct. 02, 1906 | J. Hartness | Tap and Process of Making the Same | taps and dies |
| 1,835,476 | Dec. 08, 1931 | J.C. Drader | Grinding Fixture | grinding fixtures |
| 1,918,951 | Jul. 18, 1933 | C.J. Anderson | Grinding machine | sharpening machines |
| 2,035,163 | Mar. 24, 1936 | K.W. Holmberg | Tool Holder and Guide | sharpening tool holders |
| 2,147,227 | Feb. 14, 1939 | G.B. Ambler | Drill sharpening machine | drill sharpening machines |
| 2,429,250 | Oct. 21, 1947 | E.A. Reibig, C.A. Wiken | Grinding machine | |
| 2,480,285 | Aug. 30, 1949 | E.J. Bullard | Lapping Machine | lapping machines |
| 2,617,237 | Nov. 11, 1952 | E.P. Sacrey | Cutter head sharpening attachment | handheld routers |
| 2,754,634 | Jul. 17, 1956 | W.F. French | Tooth rests for cutter grinders | cutter grinding |
| 2,787,094 | Apr. 02, 1957 | W.F. French | Cutter grinders | cutter grinding |
| 3,102,371 | Sep. 03, 1963 | C.V. Stock, E.R. Ferguson, H.H. Brelsford | Automatic Cutter Grinder | tool grinders |
| 3,566,545 | Mar. 02, 1971 | C.F. Gasek | Tap Grinder | grinding fixtures |
