A hacksaw may include a blade support frame, a handle operably coupled to the blade support frame at a first end of the blade support frame, a movable blade engagement assembly and a multi-function fixed blade engagement assembly. The multi-function fixed blade engagement assembly may be disposed at a second end of the blade support frame. The multi-function fixed blade engagement assembly may include a first clamping structure to affix a first end of a blade to the hacksaw via an engagement pin and a second clamping structure to affix a portion of the blade spaced apart from the first end to the hacksaw via a clamping or pinching force exerted on the portion of the blade. The movable blade engagement assembly may be operably coupled to the handle and to a second end of the blade. Tension on the blade may be adjustable by adjustment of the movable blade engagement assembly.

A stone cutting device configured to cut a workpiece with a plurality of cutting tools by swinging the cutting tools within a predetermined angle range. Each of the cutting tools includes: a blade extending in a length direction of the workpiece; and at least one cutting tip disposed on an end of the blade and protruding from the blade in a width direction of the blade so as to cut the workpiece while being reciprocated in a swinging motion. The stone cutting device includes a frame unit configured to combine and reciprocate the cutting tools and individually adjust tension in each of the cutting tools. The frame unit includes an actuator applying tension to the cutting tools so as to apply a load of 8 tons to 27 tons to each of the cutting tools.

A foldable bow saw movable between a functional saw condition and a folded packable condition includes a handle arm, a top bar, a short arm, a saw blade, and a lever arm, all pivotally connected one to the other with an end of the handle arm and an end of the lever arm forming free, unconnected ends of the assembly. The free end of the handle arm includes a connecting fulcrum surface adapted to removably mate with a fulcrum surface receiver in the lever arm. Rotation of the lever arm in a locking direction about the fulcrum surface moves the pivotal connection of the lever arm to the saw blade to a tensioned functional saw condition. Rotation of the lever arm in an unlocking direction allows the fulcrum surface to be removed from the fulcrum surface receiver and the assembly to be folded to the packable condition.