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).
Micro-examination report on a failed hypoid gear from an axle.
| Identifier | ExFiles\Box 136\5\ scan0214 | |
| Date | 3rd January 1930 | |
| MICRO-EXAMINATION REPORT. X2066 M680. BY.{R.W. Bailey - Chief Engineer} H11/3.1.30. Laboratory. c-c to Wor.{Arthur Wormald - General Works Manager} c to Hs.{Lord Ernest Hives - Chair} c to Sft.{Mr Swift} c-c to Sft{Mr Swift}/Mr. Pendlebury. c-c to Mr. Matthews. (Works Office). Re. Hypoid Gear from Axle which failed. Your ref: BY5/G.23.12.29. The above gear has been tested for hardness and examined under the microscope. The Rockwell figure obtained from tests made on the tops of the teeth was C58. This confirmed file tests made on the tops and sides of the teeth, which were found to be of satisfactory hardness. The core hardness of the teeth was 241 Brinell. This is also satisfactory. The case was found to be rather thicker than usual, viz., 0.046" on the concave side of the tooth examined, and 0.055" on the convex side. The micro-structure of the core was normal, but that of the case was not satisfactory, free carbide being present to a depth of 0.015" in cellular form. This is shown in the accompanying photomicrograph No. A640, which is of a transverse section through the broken-down area on the concave surface of the tooth. H1. HE | ||