Very Interesting article, especially the Kanji research for exact representation of “Iron” and “Steel”.
I wonder if this also applies, in Practice, to the German “Eiserne-Hulse” (copper washed Iron cases of WWI…Given the German punctiliousness,using Eiserne (Iron) rather than Stahl ( Steel), would, as in the Japanese situation, relate to the actual chemical composition of the Metal used.
Iron comes in two basic forms, Cast and Wrought–physical states depending on the crystalline structure and means of manufacture. Given that Eiserne -Hulse were drawn and punched, they were “Wrought” Iron sheets as a raw material. Iron, by definition, has no or very little Carbon content; any Carbon present is found as discrete Globules within the matrix of Iron (Fe) atoms.
Steel, by definition , is an alloy of Iron and Carbon in various Crystalline forms, with properties varying according to the Carbon Content. The SAE (US) system gives a good Idea of the Carbon content…Four digit number, first Digit: type of steel. Second digit: Principle alloy other than carbon; Third digit and fourth digit, Carbon content as Hundredths of 1 Percent.
So, SAE 1020 is a Carbon steel, no other major alloying material, with 0,20% Carbon…a Low grade or “Mild steel” ( Re-bar, Hardware store steel bars and Pipes, etc.)
SAE 1035 is a medium alloy Carbon steel, with 0,35% carbon…very suitable for Case Hardening, good machineability, tough…what basically was used in Mausers and Arisakas. ( small impurity percentages (such as in the Swedish ore used by Krupp for Mauser) improved the quality of the common steel.
SAE 1055 – lowest Grade of “Spring” steel…used for Cartridge clips, etc. SAE 1085: Used for making springs (leaf and coil) Hardenable and temprerable.
Steel cartridge cases made in Germany before and during WW II, and after, are made from a SAE 1025-1030 type Mild carbon sheet steel, the same as used for Automobile Body work…and was also used to make the MP40, and MP/Stg 44s etc. It is easily punched, pressed and drawn, and welds easily.
Interesting how the “F” indicator of an “Iron Brass” ( there is also a “Leaded Brass” with similar improved machineability) in Japanese Ordnance Practice has got me thinking about German work in the use of Iron and Steel in cartridge Cases.
Congratulation on the deep research required on the Japanese information. It seems that the infamous “Fire Storm” raids of 1944-45, didn’t destroy all the archives…