Radiac Abrasives

Band saws in timber mills range in size from about (4" x 22ga x 10') to (16" x 11ga x 62') and can be any of the three main different band saw type. Which are: Single-cut saws are as the name implies, have teeth on a single side. Allowing for log or work piece cutting in one direction only. Accordingly, double-cut saws have teeth on both sides. These types are designed for machinery that allows the log to be cut from either the front or the back direction of travel. "Sliver tooth" saws have teeth on both sides but they are different. The (usual) front side have teeth with a regular style tooth. The back of these saws have a longer style. The log is cut in a forward direction as with a single-cut but as the log returns, the saw de-burrs the cut(path where the saw passes) allowing for a cleaner finish. They are run for 4 to 24 hours then sent to the sawfiler for maintenance.

Gumming involves grinding the gullets of the saw teeth to a particular shape. The sawfiler uses a semi or fully automatic grinding machine for this. Band saws operate under high stress and heat and in the presence of wood chips. Carbon migrates into the steel from the wood. Gumming prevents case hardening and fatigue cracking of the band saw gullets. Resaw Band saws (teeth on one side only) may be left or right handed, depending on which way the teeth are pointing and which way the plank falls from the log when cutting. Double cut saws (teeth on both sides) are always gummed right hand teeth first.

A precise tooth profile of the gullet must be maintained for proper saw operation and wood chip removal. Ease of cutting greatly depends on this. The shape is determined by the type of wood and cutting conditions. A sawfiler will maintain the gullet shape by manually shaping the grinding wheel with an abrasive brick, and the set-up of his grinding machine. Variations include face angle, face length, back angle, gullet width and depth, and a frost notch (if necessary). Typical band saw tooth dimensions are 1-3/4" tooth space x 3/4" gullet depth x 3/4" gullet width (grinding wheel width) x 30deg face angle x 16deg back angle.