From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Fatigue limit diagram for pretempered wire steel #4.
| Identifier | ExFiles\Box 158\4\ scan0070 | |
| Date | 10th October 1936 guessed | |
| FINAL STRESS, THOUSAND LBS. PER SQ. INCH. INITIAL STRESS, THOUSAND LBS. PER SQ. INCH. ENDURANCE LIMIT ELASTIC LIMIT NO. 1, 2, 5, 7, BROKEN NO. 3, 4, 6, 8, UNBROKEN Figure 7. Fatigue Limit Diagram for Pretempered Wire Steel #4. All stresses calculated by Wahl formula. | ||