I have a couple of those also but tend to use them mostly with wood as I consider the brace a woodworking tool. There are breast drill with brace type chucks and those I consider more for metal. But that doesn't really answer your question. I think you would have no problem using them on brass. Before I used them on steel I would try and assess the hardness of the bit. Does it file easily to sharpen or do you need stones. If it files easily I wouldn't use it on steel.
Jim