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).
Firm selection, material sourcing, and the design and costing of forgings.
| Identifier | ExFiles\Box 148\5\ scan0383 | |
| Date | 20th July 1938 | |
| -4- ROY{Sir Henry Royce}/Les.1/B.20.7.38. 1. Selection of Firm (Contd:- The first Bentley going to France will be fitted with hand forged axle shafts produced in SAE.4140 material. If this test is successful, we intend to use the 10s.0d axle shaft forging. The Scottish Stampings Ltd. quite openly admit that they have quoted to our drawings knowing that their prices were not economical for certain parts, i.e. they state that their cost for small levers is generally 30% higher than the economical price. In future when enquiries are sent out, we shall ask for quotations only for parts which the particular firm consider they can produce at an economical price. 2. Material. Except for Mild Steel, all our material is electrically melted steel bought from Firths. Through buying open hearth steel at competitive prices, a saving of 25% in the cost could be made on material to the same specification. Open hearth steel nowadays is used throughout by all other motor car manufacturers. There is also a saving which could be effected by slight changes in our materials, i.e. the ultimate strength of 1% chrome steel is 95% of that of our 3% nickel and is only 65% of the cost. We shall be testing forgings produced in more economical materials. 3. Design of forging. Most forging firms consider that it is impossible to cost forgings on a price per lb. basis, but they are also naturally anxious that we should not be in a position to know the correct price. It is certainly quite impossible to buy all forgings on a price per lb. basis, i.e. Flywheels can be bought for 1½d per lb., whereas it is impossible to buy certain large forgings under 1s.0d per lb. For small control levers we pay 8s.0d per lb. It will therefore be necessary to investigate very thoroughly every class of forging and then obtain the correct price per lb. for each group. The main difficulty is that until we have shown the Forgers in general that we are not going to pay the incorrect price, all the figures for our investigation must come from firms where we are strangers. Eventually we hope to be able to pass information to the Design department which will enable them to see at a glance how the price of a forging is obtained. As far as we can see at the moment, the price per lb. will be governed by - (Contd:- | ||