  The eROSITA instrument aboard the Spectrum Roentgen Gamma (SRG) satellite has
performed its first all-sky survey between December 2019 and June 2020. This
paper presents the resulting hard X-ray (2.3-5 keV) sample, the first created
from an all-sky imaging survey in the 2-8 keV band, for sources within western
galactic sky. The 5466 hard X-ray selected sources detected with eROSITA are
presented and discussed. The Bayesian statistics-based code NWAY is used to
identify the counterparts for the X-ray sources. These sources are classified
based on their multiwavelength properties, and the literature is searched to
identify spectroscopic redshifts, which further inform the source
classification. A total of 2547 sources are found to have good-quality
counterparts, and 111 of these are detected only in the hard band. Comparing
with other hard X-ray selected surveys, the eROSITA hard sample covers a larger
redshift range and probes dimmer sources, providing a complementary and
expanded sample as compared to Swift-BAT. Examining the column density
distribution of missed and detected eROSITA sources present in the follow-up
catalog of Swift BAT 70 month sources, it is demonstrated that eROSITA can
detect obscured sources with column densities $>10^{24}$ cm$^{-2}$, but that
the completeness drops rapidly after $10^{23}$ cm$^{-2}$. A sample of hard-only
sources, many of which are likely to be heavily obscured AGN, is also presented
and discussed. X-ray spectral fitting reveals that these sources have extremely
faint soft X-ray emission and their optical images suggest that they are found
in more edge-on galaxies with lower b/a. The resulting X-ray catalog is
demonstrated to be a powerful tool for understanding AGN, in particular heavily
obscured AGN found in the hard-only sample.
