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).
Test report comparing two U.S.A. springs against drawing specifications.
| Identifier | ExFiles\Box 43\2\ Scan055 | |
| Date | 20th August 1923 | |
| REPORT SPRING F.4625 (U.S.A) Spring is stamped F.4632. Poundage 1050 lbs. Poundage given on test, 1103 lbs. The leaves are badly fitted leaving gaps of .015 between plates. Spring has 13 plates. Drawing calls for 12 or 14. Outside diameter of eye is 1.200. Drawing calls for 1.100 ± .25 Clips are out of position. Eye is out of square with length of spring .300 also with the width of Spring. Eye is oversize on 1.880 - 15. now 2.000 Initial camber of spring is 3.687. Drawing calls for 3.500 This Spring is far below an average Woodhead. SPRING F.9817 (U.S.A) Spring is stamped F.7981. Poundage 2200 lbs. On test poundage is 2812 which compares to our Piece No.F.9831 but this Spring has 12 plates, sample has only 10, and the dim.D for this piece No. should be 4.475 approx, sample is 3.600. 2 clips only are fitted. Drawing calls for 4 Clips are also fitted to the 3rd plate. Second leaf is thicker than the main leaf. Eye is out of square with length of spring .125 (OK) Eye is out of square with width of spring .020 (OK) Eye requires machining to 2.400 - 15. Now 2.500. Initial camber is 3.500. Drawing shews 2.500 1.025 dim. at Roller end is 1.200 .675 dim. at Roller end is .750 approx. Dia. of eye oversize Main Plate twisted .020. ENCLOSURE No 228 JUSTED | ||