Patent US2921877A successfully refreshed from Google Patents.
US2921877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of chromizing air hardening tool steel
Assignee: Individual
•
Filing: 1958-03-13
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Granted: 1960-01-19
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Expires: 1978-03-13
Abstract
No abstract record available.
Inventors
- 👤 George A Samuel
- 👤 Bell Jerome Victor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:45
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/28; C23C10/34; C23C10/36; C23C10/38; C23C10/40; C23C10/42; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12958
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
THE PROCESS OF CHROMIZING AIR HARDENING TOOL STEELS, WHICH COMPRISES PLACING IN A METALLIC RETORT, AIR HARDENING TOOL STEEL PARTS OF THE CLASS CONSISTING OF AISI D1, D2, D3, D4, D5, D6, 44OC, A2, A4, A5, A6, M1, M2, M3, M4, M6, M8, M10, M30, M34, M35 AND M36, ALONG WITH A SOURCE OF GRANULAR METALLIC CHROMIUM AND A HALOGEN CHROMIZING CATALYST, CLOSING THE RETORT TO THE ATMOSPHERE, HEATING UP THE RETORT AND ITS CONTENTS TO A HARDENING TEMPERATURE FOR SAID STEEL IN THE RANGE BETWEEN 1600 AND 2400 DEGREES F. AND HOLDING SAID PARTS AT SUCH TEMPERATURE FOR AT LEAST THIRTY MINUTES, AND THEN QUENCHING THE RETORT AND ITS CONTENTS IN A LIQUID COOLING MEDIUM.
Claim 2
Dependent Claim
116 words
THE PROCESS OF CHROMIZING AIR HARDENING TOOL STEELS, WHICH COMPRISES PLACING IN A METALLIC RETORT, AIR HARDENING TOOL STEEL PARTS OF THE CLASS CONSISTING OF AISI D1, D2, D3, D4, D5, D6, 44OC, A2, A4, A5, A6, M1, M2, M3, M4, M6, M8, M10, M30, M34, M35 AND M36, ALONG WITH A SOURCE OF GRANULAR METALLIC CHROMIUM AND A HALOGEN CHROMIZING CATALYST, CLOSING THE RETORT TO THE ATMOSPHERE, HEATING UP THE RETORT AND ITS CONTENTS TO A HARDENING TEMPERATURE FOR SAID STEEL IN THE RANGE BETWEEN 1600 AND 2400 DEGREES F. AND HOLDING SAID PARTS AT SUCH TEMPERATURE FOR AT LEAST THIRTY MINUTES, AND THEN QUENCHING THE RETORT AND ITS CONTENTS IN A LIQUID COOLING MEDIUM.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |