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).
Data table comparing performance characteristics (Twist, Pull, Torque) for three spring types: Std. 40/50, No. 3, and No. 4.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan77 | |
| Date | 20th March 1924 guessed | |
| -3- Spring No. | Std. 40/50. | No.3. | No.4. Twist of spg. in degrees. | Pull 'P' lbs. | Torque applied. lbs/ins. | Pull 'P' lbs. | Torque applied. lbs/ins. | Pull 'P' lbs. | Torque applied. lbs. ins. .33 | 137 | 2192 | 144 | 2304 | 129 | 2064 .67 | 212 | 3392 | 228 | 3650 | 187 | 2992 1.00 | 270 | 4320 | 336 | 5375 | 246 | 3936 1.33 | 322 | 5156 | 427 | 6832 | 310 | 4970 1.67 | 379 | 6064 | 512 | 8200 | 412 | 6592 2.00 | 442 | 7072 | 601 | 9616 | 474 | 7580 2.33 | 483 | 7728 | 673 | 10768 | 534 | 8550 2.67 | 514 | 8224 | 765 | 12240 | 602 | 9640 3.00 | 584 | 9344 | 831 | 13296 | 670 | 10720 3.33 | 645 | 10320 | 924 | 14784 | 703 | 11250 3.67 | 678 | 10848 | 1004 | 16064 | 774 | 12370 4.00 | 749 | 11984 | 1088 | 17408 | 847 | 13550 4.33 | 788 | 12608 | 1164 | 18624 | 898 | 14388 4.67 | 843 | 13488 | 1220 | 19520 | 967 | 15475 5.00 | 885 | 14160 | | | 1029 | 16464 5.33 | 944 | 15104 | | | 1092 | 17470 5.67 | 989 | 15824 | | | 1136 | 18176 6.00 | 1048 | 16768 | | | | There will be a compression equal to the pull 'P' in the rear half of the spring. Hs{Lord Ernest Hives - Chair}/AC L. | ||