A hacksaw is a hand-held saw used for making straight cuts in metal and other hard materials. It consists of a thin blade with very fine teeth held under tension in a steel frame. The teeth can be placed so that they face away from the handle or the opposite way. On the push stroke the arch of the steel frame bends a little releasing the tension on the blade. If the labeled side is placed upward when mounting the blade, the teeth will face the handle resulting in sawing action by pulling. The blade can be turned at a right angle to the frame for long cuts by rotating the bolts in their square holes. It is normally quite brittle and may snap unless care is taken.
A junior hacksaw is a smaller version of the standard hacksaw and is ideal for cutting small delicate pieces of work where the weight alone of the standard hacksaw may cause damage to the workpiece. Also, being smaller it is easier to use in confined spaces.
A mini hacksaw that accepts the same blades as a regular hacksaw but holds them in a small handle without tension. It is used for close-quarter metal cutting.
A panel hacksaw eliminates the frame, so that the saw can cut into panels of sheet metal without the length of cut being restricted by the frame.
Also see jig saw.