The sanctions, which ban the companies from doing business with the US government and US companies, were based on the Iran Nonproliferation Act of 2000, which aims at preventing Teheran from developing nuclear weapons.
The US has accused Iran of seeking to develop nuclear arms under the cover of its civilian nuclear energy program.
"These entities will be sanctioned based on credible information that they transferred equipments and technologies referred on the multilateral control lists to Iran," US State Department spokesman Adam Ereli said. "They are serial offenders."
The Chinese companies hit were the public company China National
Aero-Technology Import and Export Corporation, missile builder China North Industries Corp (Norinco), the chemical equipment group Zibo Chemet Equipment Corp, Hongdu Aviation, Ounion International Economic and Technical Cooperative Ltd, and Limmt Metallurgy and Minerals.
Two Indian chemical groups were also cited: Sabero Organics and Sandhya Organics.
Also cited was Austrian firearms maker Steyr-Mannlicher.
Mr Ereli did not provide details on what the companies supplied to
Iran, but stressed the credibility of the information on which
Washington based the sanctions, which took effect on December 23.
He noted that Norinco, a leading Chinese defence industry conglomerate, is a repeat offender.
He also praised the Austrian government for its cooperation in the case of Steyr-Mannlicher, suggesting as well that the sanctions on Steyr could be lifted quickly.
Some 40 companies have been sanctioned since the establishment of the Iran Nonproliferation Act.
"It's an important and effective tool in constraining Iran's efforts to develop missile and WMD (weapons of mass destruction) capabilities," Mr Ereli said.