A saw blade for use on a circular saw to cut drywall board is formed of thin metal and includes generally rectangular teeth formed along the perimeter of the saw blade. The saw teeth have an outer edge along a circle centered on a center of the blade and teeth edges substantially perpendicular to the outer edge. The teeth are in the plane of the saw blade. A power saw using the saw blade has a dust collection housing around a portion of the blade with an air filtration apparatus connected to the dust collection housing. A shoe of the power saw is adjustable to vary the cutting depth of the saw blade and a compressible extension of the dust collection housing is in contact with the shoe. A laser line projector is mounted on the saw and projects to a laser line target connected on an edge of the drywall board. The target disengages from the edge of the drywall board upon the saw reaching the target and the target engages the saw. A saw blade for small hand tools is also provided.