Pretty much is correct, but you should be aware of some exceptions. The M39 thread is fairly standard, but there are other sizes out there. They require different lensboards. You also have to watch the back focus length (the distance between the back of the lens and the negative). Some enlargers will not focus using short focal length lenses like the 28mm Companon-S. Other enlargers do not have enough bellows draw to focus longer focal length lenses.
Originally Posted by David A. Goldfarb