 Skil celebrated the 75th anniversary of the Model 77 in 2012.During World War II, Skil developed the PS-12 circular saw for military applications by mounting an air-driven Thor motor on a worm-driven saw for use in several types of construction.Manufactured in camouflage colors, with saw blade painted black and the body a greenish color, the saw worked just about everywhere, including underwater to cut piles or timbers.