Abstract: A collapsible hand saw features an elongated tubular frame member with a hollow interior that runs longitudinally therethrough. First and second arms are removably engaged to the tubular frame near first and second ends of thereof, to span outward from an underside thereof in a common direction. Each arm, near a distal mounting end thereof is configured for selective coupling to a bowsaw blade at a respective mounting hole therein near a respective end thereof. An adjustable tensioner is connectable between the frame member and the first arm, and when tightened, pulls the respective mounting end of said first arm away from the second arm and toward the first end of the frame member to tension the blade. The hollow interior of the frame member accommodates simultaneous storage therein of at least the first and second arms, the adjustable tensioner, and one or multiple blades.