Hi Herik

From what I have learned about the German (and possibly other European) typewriters, the 23 refers to the pitch of the escapement or the space between characters. The pitch of North American typewriters is measured in "characters per inch" (CPI), whereas the pitch of German typewriters is measured in millimeters per character. 23 is 2.3 mm per character and 25 is 2.5 mm / character.

If you are familiar with nuts and bolts, threads are measured in the same way. Imperial or standard bolts are measured by the diameter of the bolt and the threads per inch, for example, 1/2"- 13 means the bolt diameter is 1/2" and the thread pitch is 13 threads per inch. Metric bolts are measured by bolt diameter and distance in millimeters between the threads, for example M12 - 1.75 means the bolt diameter is 12mm and the thread pitch is 1.75mm from crest to crest of the threads. Clarification or correction welcome and I hope this gives you something with which to work,

Sky

Hi Again Henrik

Looking at my SG-3, the type size and pitch of the escapement are built into the main body of the machine. The number on the type scale refers to the alignment markings. For example, if you were to swap a 23 carriage for a 254 carriage, the typewriter would still type just fine. The only problem you'd run into is the typed letters would not align with the graduations on the type scale. One of my SG-3's has a 4.2 mm pitch (6 cpi) and the other is 2.54 (10 cpi). If I were to swap the platens, both machines would still type perfectly.

From what I understand, the main reason for the type scales is so that if an incomplete page of type is removed from the machine, it can be reinstalled at a later date using the graduations on the type scale to align the page to the existing type so typing can be seamlessly continued. This would be impossible if the type scale didn't match the type size of the machine.

So, to answer your question, yes the machine would work correctly, and by swapping two 23 carriages, you would be able to re-insert a partial page of type and align it so typing could be continued. Hope this makes sense,

Sky