  AIMS: We checked a sample of 545 F stars within 50 pc for wide companions
using existing near-infrared and optical sky surveys. METHODS: Applying the
common proper motion (CPM) criterion, we detected wide companion candidates
with 6-120 arcsec angular separations by visual inspection of multi-epoch
finder charts and by searching in proper motion catalogues. Final proper
motions were measured by involving positional measurements from up to eleven
surveys. Spectral types of red CPM companions were estimated from their
absolute $J$-band magnitudes based on the Hipparcos distances of the primaries.
RESULTS: In addition to about 100 known CPM objects, we found 19 new CPM
companions and confirmed 31 previously known candidates. A few CPM objects are
still considered as candidates according to their level of proper motion
agreement. Among the new objects there are nine M0-M4, eight M5-M6, one
$\approx$L3.5 dwarf (HD 3861B), and one white dwarf (WD) (HD 2726B), whereas we
confirmed two K, 19 M0-M4, six M5-M6, two early-L dwarfs, and two DA WDs as CPM
companions. In a few cases, previous spectral types were available that all
agree well with our estimates. Two companions (HD 22879B and HD 49933B) are
associated with moderately metal-poor Gaia benchmark stars. One doubtful CPM
companion, spectroscopically classified as WD but found to be very bright
($J$$=$11.1) by others, should either be a very nearby foreground WD or a
different kind of object associated with HD 165670.
