Iron Knuckle Sash Lock Iron Knuckle Sash Lock is meant for use with double hung windows. The lock comes with two pieces, the latching part, and the receiver which gets overlapped. These were found on most double hung sashes in New Orleans that predated the 1910’s. The base of the latching part measures 1-7/8″ x 13/16″. The base of the receiver measures 1-7/8″ x 3/4″. It is made of cast iron and painted black.
