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).
Test data for Smithermet 'J' Filling, detailing shutter pull and push forces at various temperatures.
| Identifier | ExFiles\Box 39\4\ Scan238 | |
| Date | 20th March 1931 | |
| SMITHERMET. "J" FILLING. SPECIAL:- PROVISION MADE FOR OPENING SHUTTERS IN THE EVENT OF THE BELLOWS BEING PUNCTURED. TEMP °C | SHUTTERS CLOSED Pull-LB | SHUTTERS CLOSED Push-LB | SHUTTERS OPEN. Pull-LB | SHUTTERS OPEN. Push-LB 20°C | 39.2 | | 54.4 | 30°C | 36.1 | | 52.9 | 40°C | 33.1 | | 51.4 | 50°C | 28.5 | | 46.8 | 60°C | 22.4 | | 40.7 | 70°C | 11.8 | | 33.1 | 80°C | 1.14 | | 17.9 | 85°C | | 10.5 | --- | 90°C | | 20.5 | 1.14 | 95°C | | | | 10.5 98°C | | 35.5 | | 25.5 | ||