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).
Graph showing the relationship between stress range and mean stress for Silicon Manganese Spring Steel for 10,000,000 stress reversals.
| Identifier | ExFiles\Box 112\1\ scan0075 | |
| Date | 30th December 1937 | |
| SILICON MANGANESE SPRING STEEL, FIGURES FROM LETTER FROM FIRTHS WPH/MW. 30.12.37. FIGURES ARE FOR 10,000,000 STRESS REVERSALS. Y-Axis: RANGE STRESS LBS/IN². X-Axis: MEAN STRESS LBS/IN². | ||