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).
Comparative loading tests of Stabalite and Beldalite at various temperatures.
| Identifier | ExFiles\Box 49\5\ Scan263 | |
| Date | 2nd February 1921 guessed | |
| X.4287. Extract from EFC {E. Fowler Clarke - Electrical Engineer} 2/T30.1.23. (X.1109) (3) Comparative loading tests of Stabalite and Beldalite at various temperatures. Exactly similar test pieces in stabalite and beldalite were used, the form of these being a flat disc with a central hole. The test piece was supported at its outer periphery and loaded at its inner periphery, the whole arrangement being in an oil-bath, so that the temperature can be gradually raised. The depressions were measured in mm. In the case of stabalite the depression cold at a total load of 12 lbs. was about ½ mm. and in the case of beldalite it appeared to be somewhat less than this at a total load of 25 lbs. Increase of depression in the case of stabalite began to occur very slowly at 70°C and increased to 1 mm. at the same load at about 85°C, and to 2 mm. at a reduced load of 10 lbs. at 100°C. In the case of beldalite slight increase of depression began to occur at about 65°C and in order to keep the depression the same at 70°C the load had to be reduced to 14 lbs. At this load the depression was doubled (1mm.) at 80°C and for the same depression at 95°C only 7 lbs. load was required. It may be judged from the above results that there is, as regards strength at high temperature, little to choose between stabalite and beldalite, but that if any difference exists the beldalite material is somewhat stronger. | ||