A nut splitter is a tool that helps to remove nuts that are stuck or seized. It can be used on a bolt head, but it is not the ideal tool for the job. A bolt head is typically larger and more round than a nut, so it can be difficult to get the splitter onto the head. Additionally, the force required to split the nut open can cause the bolt head to break or become damaged. For these reasons, it is generally better to use a wrench or other tool designed specifically for removing bolts when working with them.