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).
Specification sheet comparing two spring types for a Bentley 111 based on static deflection and normal loads.
| Identifier | ExFiles\Box 100\1\ scan0051 | |
| Date | 27th October 1937 | |
| 27.10.37. SPRINGS OF 6.500" STATIC DEFLECTION. 750 LBS. AND 800 LBS. NORMAL LOADS. BENTLEY 111. Requested by Rm{William Robotham - Chief Engineer}/Les.{Ivan A. Leslie} | | 750 lbs. Springs. | 800 lbs. Springs. | |---|---|---| | Wire Diameter. | 0.630" | 0.635" | | Mean Dia. of Coils | 4.870" | 4.865" | | No. of Effective Coils. | 7 1/2 | 7 1/2 | | Normal Load | 1132 lbs. | 1208 lbs. | | Normal Deflection | 4.34" | 4.32" | | Maximum Load | 1598 lbs. | 1708 lbs. | | Maximum Deflection | 6.13" | 6.11" | | Maximum Stress - Uncorrected | 79,500 lbs. in.sq. | 82,800 lbs. in.sq. | | Maximum Stress - Corrected | 94,300 lbs. in.sq. | 98,400 lbs. in.sq. | | Rate | 261 lbs/in. | 279 lbs/in. | | Rate at Wheel | 114.5 lbs/in. | 122.3 lbs/in. | | ||