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).
Cost comparison between pressing and die-casting methods for sump production.
| Identifier | ExFiles\Box 111\2\ scan0249 | |
| Date | 28th September 1937 | |
| 2. REW/ad.6/EB.28.9.37. Pressing. Tooling (Dies at £350) £0. 7. 0. Material (Black sheet at 22/- per cwt.) £0. 2. 0. Welding costs. £0. 1. 6. --------- £0. 10. 6. If, as is hoped, we have a production of 100 cars per week, then we may estimate for say, a years production of 5000 sumps in which case comparative costs will be as under:- Die-casting. Melting and Pouring. £0. 0. 6. Tooling Costs. £0. 0. 7. Material costs. £0. 6. 0. Machining costs. £0. 1. 6. --------- £0. 8. 7. Pressing. Tooling costs. £0. 1. 5. Material costs. £0. 2. 0. Welding costs. £0. 1. 6. --------- £0. 4. 11. Here we see a gain of nearly 40% is evident for the pressed sump, and this gain will increase as production increases over 5000. If we now take the case of the Vauxhall type of sump, then it appears that our own 250 T press is too light for this work, and the tool office stipulate at least 500 T. This would mean, therefore, that the job would have to be made outside, and it is extremely difficult to make any allowance for this. We do not think however, that this increase in cost will take the pressed steel sump greatly over the die-casting. There | ||