Iron, 8 ¾” length. Excavated from a Hudson River Valley camp site about 1970. See Collector’s Illustrated Encyclopedia of the American Revolution, Neumann, p.263 #10 for a group of related files from a British campsite of 1775. The author states that they are hand cut, but in fact we know that indexing machines, similar to clock escapement were used to uniformly incise the teeth before hardening.  This fine toothed example would have been used for gun and cannon lock repairs or as otherwise needed. Heavily encrusted from burial.