| All Patents in class 73/83 |
Patents 1 -
7
of 7
      |
| Number | Date | Patentee | Title | Type |
| 1,516,207 | Nov. 18, 1924 | S.P. Rockwell | Hardness-testing machine | metal hardness testers |
| 1,516,208 | Nov. 18, 1924 | S.P. Rockwell | Hardness-testing machine | metal hardness testers |
| 1,885,972 | Nov. 01, 1932 | C.H. Wilson | Hardness testing gauge | metal hardness testers |
| 2,726,540 | Dec. 13, 1955 | L. Small, M.G. Antonik | Hardness testing apparatus | metal hardness testers |
| 2,844,957 | Jul. 29, 1958 | L. Small | Motorized hardness tester | metal hardness testers |
| 2,986,030 | May 30, 1961 | L. Small | Hardness testing apparatus | metal hardness testers |
| 3,084,538 | Apr. 09, 1963 | H. Small, L. Small | Tester for plastic deformation and elastic deformation of tested materials | metal hardness testers |
