United Heavy Machinery or Uralmash-Izhora Group, (Russian: Объединенные машиностроительные заводы, romanized: Objedinennye Mashinostroitelnye Zavody, OMZ) is a large Russia-based international heavy industry and manufacturing conglomerate.

OMZ manufactures a wide range of steel, custom and industrial components for nuclear power plants, petrochemical and mining operations and utilities.

[3] As a Russian open joint-stock company, shares in OMZ may be publicly traded subject to terms of constitutive documents and merger agreements.

OMZ is a 50% owner of the Uralmash Machine-Building Corporation formed in a 2007 agreement with Metalloinvest.

[4] The company's shares were delisted from the Moscow and London stock exchanges in 2014 "due to the economic inexpedience of supporting the insignificant free-float of less than 0.33% of the capital.