Band Saw

What is a Band Saw?

The bandsaw is useful for cutting stock to size and roughing out shapes. It contains a serrated blade that forms one continuous loop. The blade is stretched over two pulleys, the upper one idle, the lower one driven by a variable speed electric motor.

The blade itself is housed in a metal case, visible only where the cutting work is done, in the area immediately above the worktable. Two sets of blade guides keep the blade aligned. One set is fixed below the tabletop, and the other is adjustable to varying heights above the table. The tension of the wheel is set by an adjustment located on the upper wheel housing. Another adjustment controls the tracking of the blade, which should travel at the center of the wheels.

The blade travels in one direction at a great rate, typically two to three thousand feet per minute.

Band saws vary greatly, large ones have been used to saw gigantic redwood trees into lumber; several very popular models these days fit on benchtops. The size of the tool is identified by the depth of the saw’s throat, namely the clearance between the blade and the vertical housing at the rear of the tool (which is, in turn, determined by the diameter of the wheels on which the saw turns). (Common home workshop sizes include ten-, twelve-, fourteen-, sixteen-, and eighteen-inch sizes, but in industry band saws with throats of up to forty-eight inches are common. The capacity of the tool is identified by the depth of the cut the tool will make. A twelve-inch band saw is adequate for most home workshop jobs, typically cutting up to a six-inch capacity. (Cabinetmakers would do well to opt for a larger one, perhaps one with a sixteen- or twenty-inch throat.)

The blades for band saws come in a variety of sizes and types. Each is identified by the number of points (teeth) per inch, the gauge (thickness) of the blade, and its width. Most band-saw blades are between an eighth of an inch and a half inch wide, though larger blades are to be found in bigger machines. The spacing and configuration of the teeth vary depending upon the purpose to which the blade is to be put.

The narrower the blade, the tighter the curve that can be cut with it. An eighth-inch-wide blade will cut a radius of about a quarter inch; a quarter-inch blade will cut a three-quarter-inch hole; a three-eighths blade a one-inch radius; and a half-inch blade nothing tighter than a one-and-a-quarter-inch arc.

As with saber and other saw-blades, more, smaller teeth are suited to cutting metal (in the range of twenty-four teeth per inch) while fewer, larger teeth are used to cut wood. A coarse-toothed band-saw blade with, say, six teeth per inch is best suited to rough-cutting thick lumber, while finer teeth produce a smoother cut.

Band-saw blades also have varying kinds of teeth. Some have cutting teeth set to either side, like those on a handsaw, but with unset teeth called rakers interspersed; others have wavy-set teeth, on which the teeth are set sequentially at a greater (then lesser) distance from the thickness of the band, producing the wavy appearance. Blades with wavy-set teeth are best suited to cutting metal, while blades that have raker teeth, which clear the waste efficiently from the kerf, are best for wood and coarse metals.