The blade is held on the arbor by the arbor nut. A saw is usually equipped with several throat plates, containing throats of various widths. A wider throat is required when a dado head is used on the saw. A dado head consists of two outside grooving saws (which are much like combination saws) and as many intermediate chisel-type cutters (called chippers) as are required to make up the designated width of the groove or dado. Grooving saws are usually I/S-inch thick; consequently, one grooving saw will cut a 1/8-inch groove, and the two, used together, will cut a 1/4-inch groove. Intermediate cutters come in various thicknesses.

Observe the following safety precautions when operating the tilt-arbor table bench saw:

Do not use a ripsaw blade for crosscutting or a crosscut saw blade for ripping. When ripping and crosscutting frequently, you should install a combination blade to eliminate constantly changing the blade. Make sure the saw blade is sharp, unbroken, and free from cracks before using. The blade should be changed if it becomes dull, cracked, chipped, or warped.

Be sure the saw blade is set at proper height above the table to cut through the wood.

Avoid the hazard of being hit by materials caused by kickbacks by standing to one side of the saw.

Always use a push stick to push short, narrow pieces between the saw blade and the gauge.

Keep stock and scraps from accumulating on the saw table and in the immediate working area.

Never reach over the saw to obtain material from the other side.

When cutting, do not feed wood into the saw blade faster than it will cut freely and cleanly.

Never leave the saw unattended with the power on.

Band Saw

Although the band saw (figure 3-3) is designed primarily for making curved cuts, it can also be used for straight cutting. Unlike the circular saw, the band saw is frequently used for freehand cutting.

The band saw has two large wheels on which a continuous narrow saw blade, or band, turns, just as a belt is turned on pulleys. The lower wheel, located below the working table, is connected to the motor directly or by means of pulleys or gears and serves as the driver pulley. The upper wheel is the driven pulley.

The saw blade is guided and kept in line by two sets of blade guides, one fixed set below the table and one set above with a vertical sliding adjustment. The alignment of the blade is adjusted by a mechanism on the backside of the upper wheel. Tensioning of the blade - tightening and loosening-is provided by another adjustment located just back of the upper wheel.

Cutoff gauges and ripping fences are sometimes provided for use with band saws, but you'll do most of your work freehand with the table clear. With this type of saw, it is difficult to make accurate cuts when gauges or fences are used.

The size of a band saw is designated by the diameter of the wheels. Common sizes are 14-, 16-, 18-, 20-, 30-, 36-, 42-, and 48-inch-diameter wheel machines. The 14-inch size is the smallest practical band saw. With the exception of capacity, all band

Figure 3-3. - Band saw.