| All Patents in class 148/645 |
Patents 1 -
6
of 6
      |
| Picture | Number | Date | Patentee | Title |
 | 67,734 | Aug. 13, 1867 | H. Disston | Improvement in Hardening and Straightening Steel Blades |
 | 86,286 | Jan. 26, 1869 | H. Disston | Improvement in Device for Simultaneously Hardening and Straightening Circular-Saw Blades |
| | 88,585 | Apr. 06, 1869 | G.H. Porter | Improved Process of hardening Steel |
 | RE7,464 | Jan. 16, 1877 | G.F. Simonds | Improvement in Tempering and Forming Article of Steel |
 | RE7,465 | Jan. 16, 1877 | G.F. Simonds | Improvement in Tempering and Forming Article of Steel |
| | 2,867,556 | Jan. 06, 1959 | G.E. Tegen | Method of Flame Hardening |
