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).
Results of Brinell hardness tests on various spring leaves.
| Identifier | ExFiles\Box 80\2\ scan0220 | |
| Date | 19th July 1917 | |
| X2628 BRINELL TESTS - contd. Spring F.7787 1900 lbs. Leaves. | Brin: | Remarks. | Hrs.run. 1 | 429/415 | Broken 2 | 352 | Cracked. 3 | 388 | " 4 | 388 | " 5 | 388 | O.K. 6 | 388 | O.K. 21hrs.15 mins. CH Spring F.7788 (tapered ends) 2000 lbs. Leaves. | Brin: | Remarks. | Hrs.run. 1 | 401 | O.K. 2 | 388 | O.K. 3 | 401 | O.K. 4 | 401 | O.K. 5 | 388 | O.K. 6 | 388 | O.K. 21 hrs. 15 min Spring 363.Z. C2. 2216 lbs. Leaves. | Brin: | Remarks. | Hrs. run. 1 | 388 | Cracked. 2 | 388 | Broken. 3 | 415/388 | " 4 | 401 | O.K. 5 | 352 | O.K. 6 | 388 | O.K. 9 hrs. 15 mins. R.R. 199 (250T) (SD676-19-7-17) M.P.18685 | ||