think they're Soviet or Polish (pre-1989)
Hello!
Yes, these are indeed Soviet-made vises. Their jaw width is 2 3/8 inches (60 mm). They were manufactured at the Krasnogorsk Cement Machinery Plant (Красногорский завод цементного машиностроения).
The plant was founded in 1932 in the village of Pavshino (Павшино), near Moscow, and was originally named "Standard-Concrete No. 1" (Стандарт-бетон №1). The enterprise produced high-strength reinforced concrete beams, columns, pipes, and large-format slabs for the construction of the Moscow Metro and the Moscow-Volga Canal, as well as for the reconstruction of the capital's telephone network.
In the 1930s, the village of Pavshino and several neighboring villages merged to form the town of Krasnogorsk (Красногорск).
After World War II, the focus of the "Standard-Concrete No. 1" enterprise shifted to the production of machinery. This change occurred after equipment from the Messerschmitt company was brought to Krasnogorsk from Germany as war reparations. The plant was subsequently renamed the "Pavshino Mechanical Plant" (Павшинский механический завод).
Foundry and forging/blank-preparation workshops came online in 1949, followed by pattern-making and gearbox workshops in 1954. The plant manufactured kilns for drying and firing clinker, conveyors, tower cranes, and dredgers.
Production of "consumer goods" — including vises — began in 1956. Early models featured a different stamp: the initials "П.М.З." enclosed within a diamond shape (P.M.Z. —
Pavshinskiy
mekhanicheskiy
zavod). A later version of the stamp was registered in 1961.
From 1965, the plant operated under the Ministry of Construction Machinery Manufacturing and was renamed the "Krasnogorsk Cement Machinery Plant". In addition to its previous product line, it began manufacturing cement tanker trucks and dump trucks. Its products were exported to Eastern Bloc countries, China, Vietnam, Mongolia, Iraq, Syria, Ceylon, and Cuba.
In 1991, following the collapse of the USSR, the state-owned plant was reorganized into the "Betsema" (Бецема) joint-stock company (a name formed by combining parts of the names of its founders: the Dutch conglomerate "Begemann" and the state-owned "Tsemmash"). The enterprise remains in operation today, though it has not produced vises since 1987.
I have links to the plant's website—which details its history—as well as photographs of early vises, but I will not include them in this post; I was previously banned for a similar post containing photos.