A backsaw is so named because it is any of a variety of saws that employ the use of a reinforcement spine on the back — or side opposite the blade. The spine runs the length of the blade and into the handle and provides the strength of the saw, allowing for finer cuts and more precise control in woodworking. Because the backsaw has the ability to make fine cuts, it is often used to make wooden joints and fittings. A backsaw is common in the toolboxes of cabinetmakers, furniture makers, or other woodworkers who require fine cuts or joints. The thinner blade leaves a smaller kerf – or the width of the cut – thereby cutting less material width-wise than thicker blades.
While the spine of a backsaw provides the stiffness for strength, preventing the blade from bending, the teeth of the blade make the fine cuts possible. The blade of a backsaw is typically anywhere between eight to fourteen inches long (20.3-35.6 cm) and contains eleven to fourteen closely spaced teeth per inch (2.54 cm). The backsaw’s blade must be very thin to accommodate for fine cuts, but the spine is necessary to provide sufficient stiffness. Because the spine is fixed to the back of the blade, the depth to which the backsaw can cut is limited. However, this is typically not a problem because the types of cutting the backsaw is used for generally do not call for much depth.
Most backsaws have a pistol-grip handle, but some, such as the Gent’s Saw, may use a straight handle instead. One of the most common types of backsaw is the Miter Saw, which employs the use of a miter – or guide – box to hold the blade steady. This method of cutting is especially useful for cutting angles. Not all Miter Saws are backsaws, however.
The Tenon Saw is another common backsaw, a fine-toothed saw used to cut joints or tenons. The Dozuki Saw is a Japanese backsaw that is similar to the other varieties, but unlike the common backsaws mentioned above, the Dozuki cuts on the pull stroke rather than the push stroke. This allows for increased control through the cut.