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).
Complaints of studs pulling out of aluminium and Mr. Royce's recommendation for thread length.
| Identifier | WestWitteringFiles\A\July1917\ Scan0 | |
| Date | 3rd July 1917 | |
| To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to EH. c. to EP.{G. Eric Platford - Chief Quality Engineer} E3/B2:7:17. ORIGINAL X. 3115. Re Studs in Aluminium. There have, from time to time, and recently, been complaints of studs pulling out of aluminium. We have not a stud list at St.{Capt. P. R. Strong} Margaret's, but believe the studs commonly in use at the present time are those that were made some years ago for general purposes. I have taken this matter up with Mr. Royce, and he agrees that any stud used in aluminium ought to have a length of thread equivalent to nearly two diameters. This is the maximum length to which we ever go for any solid tapped piece, the reason being that threads get out of pitch, and the pieces turn more tightly as they become fully engaged. Mr. Royce thinks that in the case of a steel stud in an aluminium casting with a thread two diameters long, that the bearing pressure on the thread will adjust itself when the load comes on, owing to the softness of the aluminium. Would you kindly send a list of what studs you are using to St.{Capt. P. R. Strong} Margaret's. E.{Mr Elliott - Chief Engineer} RECEIVED 3 JUL 1917 | ||