| Year | 1966 |
| Date | 03-Jun |
| Volume | 132 |
| Issue | 3,298 |
| Page | 490 |
| Category | For the Schools |
| Part | |
| Title | Hardening and Tempering |
| Author | Duplex |
| Notes | Steels suitable for making tools, methods of heating the work, blowers and compressors, bottled gas equipment, the electric muffle, the brazing hearth, methods of hardening |