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).
A.E.C. Specification No. 21 for Cast Iron Liners, detailing chemical analysis and hardness limits.
| Identifier | ExFiles\Box 132\4\ scan0034 | |
| Date | 1st June 1935 guessed | |
| A.E.C. Specification No. 21 Specification for Cast Iron Liners, etc. Chemical Analysis. Total Carbon ... ... ... 3.00—3.50% Combined Carbon ... ... ... 0.45—0.85% Silicon ... ... ... 1.80—2.30% Manganese ... ... ... 0.60—1.20% Sulphur ... ... ... Under—0.12% Phosphorus ... ... ... 0.50—0.80% Nickel ... ... ... 0.10—0.65% Chromium ... ... ... 0.10—0.30% To be cast as specified on our drawings, castings to be clean, sound, close grained, free from drawn or chilled spots, scabs or other defects, and capable of being machined by usual methods. Castings to be either in the “AS CAST” or “HEAT TREATED” condition according to our drawing and order, and to the following Brinell Hardness Limits. AS CAST. HEAT TREATED. Brinell Hardness No. 225—275 400—500 21A. Drawings calling for 21A are to be to the above Chemical Analysis with the exception that the Phosphorus content is to be 0.8 to 1.1%. "Condition" is to be "As Cast" Brinell Hardness No. 225 - 275. ST.{Capt. P. R. Strong} 89793. | ||