Husband material is a phrase that does a lot of work and explains very little. None of what follows is a personality type. These are behaviours that tend to predict whether living with someone is manageable, which is a duller question than romance usually asks.
He handles money without drama

This is not about how much he has. The signal is whether he can say what he earns, what he owes and what worries him without the conversation turning into a performance. Financial secrecy is one of the more reliable predictors of trouble later, and it usually shows up early in small evasions.
He notices domestic work before being asked

The gap between helping and noticing is the whole thing. A man who waits to be told what needs doing has quietly made his partner the manager, and that arrangement is exhausting in a way that is hard to complain about without sounding petty. Noticing is learnable, which is the encouraging part.
He has kept his friendships

Long friendships suggest he can tolerate other people over time, including when they annoy him. Men who arrive with no close relationships outside work often make a partner responsible for their entire social and emotional life. That is a heavy job to hand someone without mentioning it.
He apologises without conditions

An apology with a clause attached is a negotiation. The useful version names the thing, does not explain why it was reasonable at the time, and does not require reassurance afterwards. It is rarer than it sounds.
He is reliable about unimportant things

Whether he turns up when he said he would, on a day nothing depends on it, tells you more than his behaviour in a crisis does. Most people rise to emergencies. Far fewer are consistent on a Tuesday.
He manages his own health

Booking his own appointments, taking medication he has been prescribed, seeing a GP before something becomes urgent. Partners very often end up running a man’s health by default, and it is one of the least discussed forms of unpaid work in a relationship.
He is decent to people who cannot help him

Waiters, call centre staff, the person who has just made a mistake in front of him. How someone behaves with no audience and nothing to gain is a better sample of character than how he behaves with you, because with you he is trying.
He can disagree without escalating

Conflict is unavoidable and the only real question is what shape it takes. Someone who can stay in an argument without going silent, raising his voice or turning it into a referendum on whether he is a good person is considerably easier to live with over decades.
He has something of his own

A man with nothing going on will eventually make his partner the entire point of his life, and being on the receiving end of that is unpleasant. It does not have to be impressive or interesting to anyone else. It has to be his.
He treats your people as real people

This is not charm, which is easy to sustain for one evening. Watch whether he remembers what your family and friends told him, asks after them weeks later, and behaves the same way when there is nothing in it for him.
What the list does not cover

None of this predicts whether you will actually enjoy living with someone, which stays stubbornly unpredictable. These are floor conditions rather than a description of a good marriage, and plenty of men who tick every box are still wrong for a particular person. The list is more useful for spotting what is missing than for confirming what is there.