| All Patents in class 73/81 |
Patents 1 -
8
of 8
      |
| Picture | Number | Date | Patentee | Title |
| | 1,294,171 | Feb. 11, 1919 | S.P. Rockwell, H.M. Rockwell | Hardness-tester |
 | 1,768,639 | Jul. 01, 1930 | W.F. Shore, A.F. Shore | Gauge |
| | 1,770,045 | Jul. 08, 1930 | C.P. Shore, A.F. Shore | Apparatus for Measuring the Hardness of Materials |
 | 1,770,046 | Jul. 08, 1930 | A.F. Shore | Apparatus for Measuring the Hardness of Materials |
 | 1,890,923 | Dec. 13, 1932 | C.H. Wilson | Test piece support for hardness testers |
 | 2,643,460 | Jun. 30, 1953 | E.C. Zirzow, W.P. Adair, H.W. Dietert | Hardness Testing Indicator |
| | 3,136,153 | Jun. 09, 1964 | S. Kornblau | Durometer |
| | 3,485,091 | Dec. 23, 1969 | S. Kornblau | Durometer |
