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. 22 for the chemical composition and hardness of cast iron for piston rings.
| Identifier | ExFiles\Box 132\4\ scan0035 | |
| Date | 1st June 1935 | |
| A.E.C. Specification No. 22 CAST IRON FOR PISTON RINGS. Rings to be made from Chill Castings to the following composition :— Chemical Analysis. Total Carbon not more than 3.5% Combined Carbon ... ... 0.45 to 0.80% Silicon ... ... 1.80 to 2.50% Sulphur not more than 0.12% Phosphorus not more than 1.00% Manganese ... ... 0.4 to 1.20% Rings to be in the condition stated on the drawing. As Cast condition to Hardness Limits 225 to 275. Heat-treated condition to Hardness Limits 400 to 475. Both measured on a Vicker's Machine, using a pyramid diamond 30 kilogram load 1 1/3 in. objective. To be sound, close grained and free from any defects. 89981/6/35 | ||