It is well known that Muslim men are prohibited to wear gold rings. This is clearly stated in the Prophetic hadiths. `Ali (may Allah be pleased with him) reported that the Prophet (peace and blessings be upon him) took some silk in his right hand and some gold in his left, declaring, “These two are haram for the males among my Ummah” (Ahmad). Thus, if the bronze ring contains gold or is coated with gold, it is prohibited for Muslim males to wear it.
The Islamic Religious Council of Singapore, states the following: If the bronze ring is made purely from metals other than gold, then Muslim men are allowed to wear it. But if the ring is coated with gold, or it contains a certain percentage of gold, then it is forbidden for Muslim men to wear it.