Export /Import of valid model leads to lost of tolerances

Export of the attached model Attachment 1 (BREP) (solid) and following import leads to lost
of tolerances. As result it (just expoted model) can't be opened in other
CADs(such as catia or pro/e) software correctly.
Tolerances before export:
========================
Tolerance MAX=0.0044180707084453498 AVG=0.00028114085093888834
MIN=1.[revision removed]-005
FACE : MAX=1.[revision removed]-005 AVG=1.[revision removed]-005
MIN=1.[revision removed]-005
EDGE : MAX=0.0044180707084453498 AVG=0.00027160806391925076
MIN=1.[revision removed]-005
VERTEX : MAX=0.0044180707084453498 AVG=0.00030899891032537525
MIN=1.[revision removed]-005

Tolerances after re-import:
===========================
Tolerance MAX=383.40233327855935 AVG=10.160839404293757 MIN=9.[revision removed]-008
FACE : MAX=9.[revision removed]-008 AVG=9.[revision removed]-008
MIN=9.[revision removed]-008
EDGE : MAX=383.40233327855935 AVG=6.9339315386751332 MIN=9.[revision removed]-008
VERTEX : MAX=383.40233327855935 AVG=12.639639541589665 MIN=9.[revision removed]-008

Script to reproduce the problem.
restore Attachment 1 (BREP) s
checkshape s
stepwrite m s st.stp
stepread st.stp a *
toler a_1