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).
Comparison of material usage and cost between Hexagon and Square bars, recommending the adoption of Hexagon bolts.
| Identifier | ExFiles\Box 148\5\ scan0177 | |
| Date | 7th July 1937 | |
| -2- RHC.{R. H. Coverley - Production Engineer}6/HJ.7.7.37.Cont'd.{John DeLooze - Company Secretary} ½" Hexagon 7.500 lbs. per 10 ft. = 2986 ft. per ton. ½" Square 8.490 lbs. per 10 ft. = 2638 ft. per ton. Increased length of Hexagon compared with Square bar .... 348 ft. per ton. ¾" Hexagon 16.800 lbs. per 10 ft.= 1333 ft. per ton. ¾" Square 19.120 lbs. per 10 ft. = 1171 ft. per ton. Increased length of Hexagon compared with Square bar .... 162 ft. per ton. Therefore taking into account the increased length on the various sizes of Hexagon as compared with Square bar, and the increased number of parts that would be produced, shows a reduction in bar material costs of - £9. 6. 9d. per Ton for ¾" Hexagon Bar. £7. 11. 0d. " " ½" " " £5. 18. 0d. " " ¾" " " In view of the above Hexagon bolts are recommended for adoption in place of Square headed bolts. RHC.{R. H. Coverley - Production Engineer} | ||