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).
The manufacturing process for washers, comparing the use of heat-treated bar versus post-machining heat treatment.
| Identifier | ExFiles\Box 36\1\ scan 149 | |
| Date | 25th November 1927 | |
| -2- RHC{R. H. Coverley - Production Engineer}1/BE.25.11.27. The reason we use Heat-Treated Bar is because it permits of washers being completed in the one operation, whereas if washers were machined, then Heat-Treated, whilst more uniform brinell hardness may be guaranteed, there would be a certain amount of distortion, which unless it was corrected or provided for during grinding of bore (which would be necessary if washers were produced this way) spring would not be square when in position. We have taken some standard washers and find that brinell figure is the same as experimental (standard practice is to produce from Heat-Treated Bar). It would no doubt improve the figure of hardness if we gave a higher brinell figure on the bar, which would bring the core figure within drawing limits. We are taking this up with the D.O. but do not consider that the method of producing these washers can be improved upon. RHC.{R. H. Coverley - Production Engineer} Htloveley | ||