1. Specification for aircraft material. '20' carbon steel (suitable for welding) (25/35 tonf/sq in: maximum size 6 inches diameter or minor sectional dimension). (31st January 1964) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (6 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗
2. Specification for aircraft material. Carbon-manganese steel (suitable for welding) (40/55 tonf/sq in: limiting ruling section 4 in). (31st January 1964) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (8 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗