| All Patents in class 73/83 |
Patents 1 -
9
of 9
      |
| Picture | Number | Date | Patentee | Title |
 | 1,516,207 | Nov. 18, 1924 | S.P. Rockwell | Hardness-testing machine |
 | 1,516,208 | Nov. 18, 1924 | S.P. Rockwell | Hardness-testing machine |
| | 1,762,497 | Jun. 10, 1930 | C.H. Wilson | Automatic hardness tester |
| | 1,762,498 | Jun. 10, 1930 | C.H. Wilson | Hardness-testing method and apparatus |
 | 1,885,972 | Nov. 01, 1932 | C.H. Wilson | Hardness testing gauge |
 | 2,726,540 | Dec. 13, 1955 | L. Small, M.G. Antonik | Hardness testing apparatus |
 | 2,844,957 | Jul. 29, 1958 | L. Small | Motorized hardness tester |
| | 2,986,030 | May 30, 1961 | L. Small | Hardness testing apparatus |
| | 3,084,538 | Apr. 09, 1963 | H. Small, L. Small | Tester for plastic deformation and elastic deformation of tested materials |
