Tooth pitch is measured in teeth per inch (TPI). Coarse pitch (3-8 TPI) is for thick sections and for soft materials where chips are large — it clears chips and cuts fast. Fine pitch (14-24 TPI) is for thin wall tube, sheet and hard materials where coarse teeth would catch and break. The rule of thumb is that at least three teeth should be in contact with the material at all times.
Blade material follows the cutting. Bi-metal blades have a hardened tooth edge on a flexible back and are the general-purpose choice for portable band saws and cut-off work. Carbide-tipped blades cut faster and last longer on hard and abrasive materials but cost more and are less forgiving of impact. Solid carbide is for production machines. Diamond and abrasive blades are for hardened steel and for masonry.
Blade dimensions must match the machine — length, width and thickness are all specific to the saw. A blade that is too wide will not fit the guides; too narrow and it will not track straight.
