We present the analysis of a CCD survey of 31 nearby ( \leq 110 Mpc ) edge-on spiral galaxies .
The three-dimensional one-component best fit models provide their disk-scalelengths h and for the first time their disk cut-off radii R _ { co } .
We confirm for this sample the existence of such sharp truncations , and find a significantly lower mean value of the distance independent ratio R _ { co } / h = 2.9 \pm 0.7 than the standard value of 4.5 often used in the literature .
Our data show no correlation of these parameters with Hubble type , whereas we report a correlation between R _ { co } / h and the distance based scalelength in linear units .
Compared to the Milky Way we find only lower values of R _ { co } / h , explained either by possible selection effects or by the completely different techniques used .
We discuss our data in respect to present models for the origin of the cut-off radii , either as a relict of the galaxy formation process , or as an evolutionary phenomenon .