Thumb Latches are a traditional method for the latching of ledged and braced doors and are still a very popular choice today. We offer a wide range of authentic Black Antique Iron Thumb Latch designs to suit both internal and external applications. Did You Know?? On a Norfolk Latch the handle is fitted to a backplate independently of the thumbpiece. In the case of a Suffolk Latch, the thumbpiece passes through the upper part of the handle.