Leica Thread Mount (LTM) — the original Leica screw mount introduced in the 1930s. Also used on Soviet rangefinder cameras (FED, Zorki, Kiev, early Zenit) and most enlarger lenses globally (L39 enlarger mount). One of the most common threads in the catalogue.
Note: Note: LTM pitch is 26 tpi (≈0.977mm) not a true metric 1mm pitch, but the difference is negligible for short threads.
