If a man or woman wears a ring on his or her finger, must the ring be removed before Netilat Yadayim?
In the case of a man who wears a wedding band or decorative ring (a practice which I am not necessarily advocating), the question depends on whether he customarily removes his ring when he involves himself in work such as gardening, repairs, housework, and so on. If he does remove his ring on such occasions, then he must remove it before washing Netilat Yadayim, as on his finger it would constitute a Hasisa (interruption between the water and his hand). If, however, he always keeps it on his finger, such as if he does not involve himself in hands-on labor, or if he does not mind keeping the ring on his finger when he does, then he may keep the ring on for Netilat Yadayim, as well. Even the ring is fastened tightly around his finger, he may wear it during Netilat Yadayim, as it is not considered a Hasisa in such a case. The Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933) notes that if one removes his ring before showering and swimming, as he wants to ensure not to get the ring wet, then he must remove it before Netilat Yadayim. But if he always keeps his ring on, even when bathing, then he may keep it on for Netilat Yadayim, as well.
Regarding women, many of whom wear rings, the determining factor is whether a woman removes her ring when kneading dough or performing other kitchen tasks. If she normally removes her ring when involving herself in such activities, then she must remove it for Netilat Yadayim, as well, whereas if she keeps her ring on when baking and performing other kitchen chores then she may keep it on for Netilat Yadayim, even if it is fastened tightly around her finger. However, even in such a case, if the majority of women in her locale remove their rings before doing kitchen work, then she must remove her rings before Netilat Yadayim regardless of her personal practice in this regard. It seems reasonable to assume that the vast majority of women remove their rings before baking, both to protect the ring and to prevent the dirt on the ring from coming in contact with the food. As such, women must remove their rings before washing Netilat Yadayim.
Summary: A man who wears a ring must remove it before Netilat Yadayim if he normally removes it before performing labor or before bathing or swimming. If he always keeps it on, even when engaged in these activities, then he may keep it on for Netilat Yadayim. Women must remove their rings before Netilat Yadayim.