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).
Report page detailing the dimensions and test results for a plug, including a comparison with Bologna plug dimensions.
| Identifier | ExFiles\Box 58\2\ Scan148 | |
| Date | 1st September 1934 guessed | |
| Report No. R.A.E./E.{Mr Elliott - Chief Engineer} and 1.856 -3- 4. Dimensions. The main dimensions of the plug are shown in the attached Fig.1. Departure from standard British dimensions are given in Table 2 below. Table 2. - Dimensions. | Part. | Standard dimensions. Specification E.E.141 | Bologna plug dimensions. | |---|---|---| | Terminal screw thread (length). | 9/16 inch. | 11/32 inch. | | Gland nut hexagon. | 0.710 inch-0.705 inch across flats. | 0.832 inch across flats. | | Body hexagon. | 0.920 inch-0.915 inch across flats. | 0.945 inch across flats. | 5. Examination of gland and plug body threads. Three of the plugs were examined. The effective and core diameters of the plug body threads are not in accordance with B.S. Specification No.E.9. The threads on the gland are of B.S.F. formation. 6. Twisting moment test on plug body threads. Three of the plugs were subjected to a twisting moment of 60 lb. feet on the plug body thread. No fracture occurred. Result satisfactory. 7. Gas leakage tests. Six of the plugs were tested for gas leakage. Each plug was subjected to the standard pressure temperature cycle as detailed in the sparking plug specification No.E.E.141. | ||