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).
Specifications and analysis requirements for Chevrolet piston rings.
| Identifier | ExFiles\Box 87\2\ scan0203 | |
| Date | 24th June 1936 guessed | |
| Further Particulars of Chevrolet Rings. A { To require a load of 9 lbs. min. (11 to 12 lbs. desired) (applied at 'W' and supported at 'R' to close gap in ring. B Rings must pass light gauge test 100% on circumference. C { Sides of rings must be flat within .0005" Test by { allowing rings to pass through vertical fixture by { their own weight. D Dish in ring not to exceed .0002" TESTS. Each finished ring must be capable of being treaded over a 3.313 dia. plug and still comply with specification 'A' and 'B'. MATERIAL. Material to be a close grain, high tensile gray cast-iron free from porosity and blow holes when finished; so cast and treated that the finished rings will be substantially free from unequal shrinkage strains. ANALYSIS. Total carbon 3.25 - 3.75 Manganese .50 - .80 Combined carbon .30 - .80 Phosphorus .85 max. Silicon 2.75 - 3.25 Sulphur .10 max. Rockwell hardness 1/16 ball, 'B' scale 98 s 106. Both sides to be checked. Sclerscope hardness 47-55. Tensile strength 20,000 lbs. per sq.in. Rings must be individually cast. Samples must receive engineering approval Service rings to be wrapped with a green tape. | ||