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).
Bulletin detailing the composition and naming conventions of Silchrome 'X' series valve steels.
| Identifier | ExFiles\Box 158\4\ scan0057 | |
| Date | 10th September 1936 guessed | |
| SILCHROME "X" STEELS. The following information is being sent to you for your own use. The valve manufacturers have asked us not to discuss it with their jobbers inasmuch as they have little or no information on the subject. In all probability any valves of the "X" series will only be marked Silchrome X and may or may not have the numbers to designate the analysis. We can consider all of the Silchrome X steels to be satisfactory from our standpoint for any use they may be put to in the field. During the past few months there have been some changes in the valve industry. The Wilcox Rich Corporation, Thompson Products, Toledo Steel Valve Company and the Detroit Motor Valve Company have agreed to use the same trade name for their valve steels, providing they are of the same analysis. In classifying valve names it has been decided to classify all of the steels generally considered better than Silchrome No. 1 as part of the Silchrome X series of steels. At the present time the following steels will be known to the trade as the Silchrome X series: Silchrome XB 21% chrome 1% nickel 2½% silicon .5% manganese This is a new steel and to date, although it has not been adopted by any manufacturer, it is considered to be slightly better than Silchrome No. 1. It will not be recommended for heavy duty truck engines as other of the X series are considered more satisfactory. Silchrome X-8 steel is the new name for the old 2112 analysis, (21% chrome, 12% nickel) Silchrome X-9 is the name of a slightly improved steel with the general analysis of the old material known as TPA 145W. Silchrome X-10, is the new name for a slightly improved variation of the old Ford steel, previously known as 196. This new steel now has 8% nickel instead of 6% nickel. Silchrome XCR .5% manganese .6% silicon 24% chrome 5% nickel 3% molybdenum This is an entirely new valve steel and is unique in that it has the properties generally attributed only to austenitic steel and although its analysis indicate that it is austenitic it is magnetic | ||