Machinery's Handbook, 31st Edition
BAND SAW BLADES 1243 nonferrous materials such as aluminum castings, fiberglass, and graphite. The carbide grit blade has tungsten carbide grit metallurgically bonded to either a gulleted (serrated) or toothless steel band. The blades are made in several styles and grit sizes. Both carbide grit and diamond grit blades are used to cut materials that conventional (carbon and bimetal) blades are unable to cut such as: fiberglass, reinforced plastics, composite materials, car - bon and graphite, aramid fibers, plastics, cast iron, stellites, high-hardness tool steels, and superalloys. Band Saw Speed and Feed Rate.— The band speed necessary to cut a particular material is measured in feet per minute (fpm) or in meters per minute (m/min), and depends on ma- terial characteristics and size of the workpiece. Typical speeds for a bimetal blade cutting 4-inch material with coolant are given in the speed selection table that follows. For other size materials or when cutting without coolant, adjust speeds according to the instructions at the bottom of the table.
10 12 14 16 18 20 22 24 26 28 30
0.75 1.5
1.5 2.5
2 3
3 4
4 6
5 8
0 2 4 6 8
8 12
0
50 100 150 200 250 300 350 400 450 500 550 600
Band Speed (ft/min) Cutting Rates for Band Saws
The feed or cutting rate, usually measured in square inches or square meters per minute, indicates how fast material is being removed and depends on the speed and pitch of the blade, not on the workpiece material. The graph above, based on material provided by American Saw and Mfg., gives approximate cutting rates (in 2 /min) for various variable- pitch blades and cutting speeds. Use the value from the graph as an initial starting value and then adjust the feed based on the performance of the saw. The size and character of the chips being produced are the best indicators of the correct feed force. Chips that are curly, silvery, and warm indicate the best feed rate and band speed. If the chips appear burned and heavy, the feed is too great, so reduce the feed rate, the band speed, or both. If the chips are thin or powdery, the feed rate is too low, so increase the feed rate or reduce the band speed. The actual cutting rate achieved during a cut is equal to the area of the cut divided by the time required to finish the cut. The time required to make a cut is equal to the area of the cut divided by the cutting rate in square inches per minute.
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