120 and 620 film were the same size width, length and thickness. The only
difference was the shape of the spools. The 620 spool had a very thin core
and slim ends. The 120 spool had a thicker core and fatter ends. The 620
spool and film together made a  more compact package than a spool of 120. If
I remember correctly, there were problems with film curl with 620.  There
were very few high end camera that used 620. Hasselblad always used 120.
Michael

Reply via email to