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 discussing revised specifications for brass spinnings and issues with a master plug gauge.
| Identifier | ExFiles\Box 150\3\ scan0405 | |
| Date | 18th March 1938 | |
| Copy to Roy{Sir Henry Royce}/Dn. 1280? Rm{William Robotham - Chief Engineer}/Std.2/AP. March 18th.1938 The Stainless Spinning Works, 182, Miller Street, BIRMINGHAM 6. For the attention of Mr.E.P.Blake. Dear Sirs, With regard to the brass spinnings to Ew.1664 for which you have quoted, our Mr. Dalman is today sending you a revised print which has the interal thread bottom diameter altered from 2.055-5 to 2.050+5 and specifies electro tinning and chromium plating internally. We shall require to buy these spinnings un-tinned and tin and plate them here. Mr. Dalman will no doubt communicate with you on this subject. With regard to the master plug which is being made here to pass off the production spinnings, unfortunately, owing to a misunderstanding while the thread is correct in outside diameter, angle etc., it is slightly too deep so that the bottom diameter of the thread is 1.992" instead of 2.000". This means that the plug will be quite satisfactory for passing off spinnings except in the event of the interal diameter of the spinning thread being more than .050 small, which is presumably a very unlikely occurrence especially in view of the fact that the drawing specifies a limit of +.005" (a limit by the way which could be slackened somewhat if necessary.) Accordingly we shall not scrap this gauge plug but will utilise same - however, to be on the safe side we think that when the tools are ready for trial you should check the internal diameter of the thread (2.050 + 5) to make sure that it is not seriously small. We will forward this gauge plug to you as soon as it is complete, and will be interested to try out the first spinnings on same (either here or at your works) when the tools are complete. Yours faithfully, | ||