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 metallurgical tests on various test bars.
| Identifier | ExFiles\Box 52\2\ Scan006 | |
| Date | 19th February 1920 | |
| R.H. 228a (100 T) (S.G. 642, 19-2-20) G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 251a (2) No. of Test Bar. Brinell. Ult. Str. Y.P. Elong. % 2" R.A. 5122/1 229 51.28 42.24 24.4 64.4 5122/2 Scrapped in machining. 5122/3 444 103.20 Indefinite. 14.5 47.8 5122/4 444 106.60 Indefinite. 13.5 40.8 5122/5 444 101.24 Indefinite. 16.0 49.8 5122/6 444 101.64 Indefinite. 13.4 40.5 5122/7 415 90.60 Indefinite. 13.5 46.6 5647/1 269 59.96 43.04 24.3 58.3 5647/2 477 120.48 Indefinite. 9.5 21.6 5647/3 461 107.52 Indefinite. 14.5 46.9 5647/4 514 117.64 Indefinite. 12.5 36.1 5647/5 461 106.96 Indefinite. 14.5 46.2 5647/6 477 116.16 Indefinite. 13.3 36.1 5647/7 461 105.32 Indefinite. 15.5 44.3 | ||