Sadatsuna is traditionally regarded as belonging to the lineage of ancient Hoki Yasutsuna of Hoki Province. Beginning with Yasutsuna, and including Sanemori -- traditionally said to have been his son -- as well as members of the same line such as Aritsuna, Yasuie, and Sanekage, this group is collectively referred to as "Ko-Hoki." They flourished from the late Heian period into the early Kamakura period. According to sword reference works, Sadatsuna is traditionally recorded as the son of Ohara Sanemori, though one theory holds he was Sanemori's grandson. Extant signed tachi by this smith are exceedingly few, making preserved examples with ubu nakago and legible signatures exceptionally valuable as documentary material. The prominent o-sujikai file marks seen on Sadatsuna's tangs do not appear on Yasutsuna or Sanemori, but they are observed on Aritsuna, who is also regarded as belonging to this group.

In manner of workmanship, Sadatsuna's forging shows itame mixed with mokume and flowing grain, frequently incorporating o-itame with a conspicuously standing texture known as hada-dachi. The steel intermingles chikei and dark mottled patches called jifu, producing a characteristic blackish cast, while jifu-utsuri often emerges across the ground. Compared to contemporaneous Ko-Bizen works, which the Ko-Hoki group superficially resembles, the texture of the forging possesses a more rustic, vigorous character. The hamon is typically based on suguha or ko-midare, mixed with ko-gunome, ko-choji, and ko-notare; nie adheres thickly and in places becomes rough and strongly expressed. The habuchi frequently shows hotsure, while kinsuji, nie-suji, and sunagashi run conspicuously throughout. The nioiguchi characteristically takes on an urumi tendency -- a moist, soft quality -- with a shizumi or subdued character that distinguishes it from the brighter edge lines of Ko-Bizen. Within the Ko-Hoki group, Sadatsuna's work is further distinguished by height variations in the tempering and a florid, variegated quality to the hardened edge, at times incorporating choji of somewhat larger, tufted form that reveals a perceptible Bizen temperament.

Sadatsuna's works occupy a distinctive position within the Ko-Hoki tradition. While the group as a whole shares a markedly rustic and untrammeled flavor that sets it apart from the refinement of Ko-Bizen, Sadatsuna's blades often display a particularly brilliant interplay of activities in both ji and ha. His finest examples combine a powerful and dignified sugata -- frequently retaining funbari, high koshizori, and a graceful tachi silhouette concluding in ko-kissaki -- with abundant nie and plentiful hataraki throughout the hardened edge. The comparatively well-kneaded forging seen in certain attributions, together with fine yet varied nie activities extending through both ground and edge, provide nuanced changes that elevate his best work to an especially outstanding level of craftsmanship. One signed tachi was transmitted in the Tokugawa shogunal house, attesting to the esteem in which these blades have been held. As extant works by this smith remain rare, each example carries considerable significance for the study of early Japanese swordmaking in the San'in region.