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).
Letter from Gleason Works regarding scored hypoid gears and their material specifications.
| Identifier | ExFiles\Box 111\4\ scan0062 | |
| Date | 9th September 1938 | |
| 802 GLEASON GLEASON WORKS Builders of Bevel Gear Machinery for Over Seventy Years 1000 UNIVERSITY AVENUE, ROCHESTER, N. Y., U. S. A.{Mr Adams} September 9, 1938 Rolls-Royce Ltd. Derby, England Your Reference Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}9/MH.{M. Huckerby} Gentlemen: In reply to your letter of August 30th advising that you had scored a pair of the 8/37 - 1 1/2" offset - hypoid gears on dynamometer test, we cabled as follows: "RELET AUGUST 30TH MATERIAL SAE 4620 DIRECT QUENCHED STOP PLEASE RETURN SCORED GEARS FOR INSPECTION ALSO SEND ASSEMBLY PRINT AND LOAD DATA" We are unable to account for this trouble, assuming that proper tooth contact under load, was maintained on the gears in the axle. These gears were made of the standard material for all of our hypoid gears, namely SAE 4620 steel case-hardened with following treatment: Carburize @ 1700°F Quench from box File hard-check Above specifications are noted on our detail prints #GB3377 and 8 and GB3486 and 7 forwarded with our letters of March 3rd and March 19. Specifications for this steel are: Electric furnace steel 6-8 Grain size Carbon - .17 - .22 Manganese - .40 - .60 Phosphorous (maximum) - .025 Sulphur " - .025 Silicon - .15 - .30 Nickel -1.65 -2.00 Molybdenum - .20 - .20 | ||