Wearing an Iron Ring for Men
Question

I heard that wearing an iron ring is haram (impermissible) for men. I hope you can explain the matter, with evidence.
Praise be to Allah.It was narrated from ‘Abd-Allah ibn Buraydah from his father (may Allah be pleased with them both) that a man came to the Messenger of Allah (peace and blessings of Allah be upon him) and he was wearing a ring of gold. He said: “Why do I detect the stench of idols on you?” So he threw it away. Then he came and he was wearing a ring of iron, and he said: “Why do I see you wearing the jewellery of the people of Hell?” So he threw it away. He said: O Messenger of Allah, of what should I wear (a ring)? He said: “Wear (a ring) of silver, but no more than a mithqal (a measure of weight).” Narrated by Abu Dawood, al-Tirmidhi and al-Nasai. Al-Tirmidhi said: This is a ghareeb (strange) hadeeh. It was narrated from Iyas ibn al-Harith ibn al-Mu’ayqeeb that his grandfather said: The ring of the Prophet (peace and blessings of Allah be upon him) was made of iron overlaid with silver. He said: I kept it sometimes, and Mu’ayqeeb was in charge of the ring of the Prophet (peace and blessings of Allah be upon him). Narrated by Abu Dawood and al-Nasai.
In al-Saheehayn it is narrated from Sahl ibn Sa’d al-Ansari (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said to the one who proposed marriage to the woman who had offered herself in marriage to the Prophet (peace and blessings of Allah be upon him): “Look for something (to give as a dowry), even if it is a ring of iron.” This indicates that it is permissible to wear a ring of iron, as is indicated by the hadeeth of Mu’ayqeeb. As for the hadeeth of Buraydah quoted above, there is some weakness in its isnad (chain of narration). Thus it is clear that the more correct view is that it is not makrooh (disliked) to wear a ring of iron. But wearing a ring of silver is better, because the ring of the Prophet (peace and blessings of Allah be upon him) was made of silver, as is proven in al-Saheehayn. 
And Allah is the Source of strength. May Allah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.