Toilet flanges are an integral part of a working toilet. A common choice for this flange is the ABS toilet flange. ABS toilet flanges are made of a more rigid material than the common PVC flange. Due to the rigidity of this flange, it can crack or break on installation, if too much pressure is put on it. Many ABS toilet flanges have metal rings to reinforce them. These metal rings can corrode and break, causing leaks, over time and usage. Hard water will also have an affect on them. These rings can also rust slowly, if the flange has a slight leak, loosening the connection.