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).
Replacement alloy for sand castings with bearing surfaces, detailing its superior properties.
| Identifier | ExFiles\Box 142\4\ scan0160 | |
| Date | 30th January 1936 | |
| X1203 To BY.{R.W. Bailey - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} c. to Rg.{Mr Rowledge} c. to Hs.{Lord Ernest Hives - Chair} c. to Wor.{Arthur Wormald - General Works Manager} HL1/AG.30.1.36. Laboratory. Re: Sand Castings with Bearing Surfaces. We are at present making quite a considerable number of castings in A.P. 221 (8% Copper). This alloy is used for its frictional properties. Its casting qualities are not too good. We suggest that you replace this alloy with one of the R.R.50 (type) containing 0.50% Magnesium. This latter alloy possesses superior frictional qualities and very good casting qualities; and can be used with just a stabilising treatment of 170°C., or it can be solution treated. Its hot strength is superior to either R.R.50 or AP.221, and the saving in weight over AP.221 would be 5%. When solution treated its tensile strength in sand is about 19 - 22 tons per square inch, and its elongation 1.5 - 2.5%. The 0.1 Proof Stress is 16.0 to 17.0 tons per square inch. Hl. HE | ||