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A saw filer is a person who maintains and repairs saws in a saw mill. A saw filer's work area in the mill is called the filing room.
Saws used in timber mills are very large. They need maintenance for safe operation. Repair of damaged saws requires a degree of skill. It takes a year of saw filing to become proficient.
Automated equipment has continued to be developed and implemented to improve saw repair quality, with the end goal of operational uptime and productivity.
Bandsaws in timber mills range in size from about (4" x 22ga x 10') to (16" x 11ga x 62') and can use any of the three main different saw band types:
The saw filer inspects the saw for needed repairs then gums, fits and benches the saw as necessary.
Gumming involves grinding the gullets of the saw teeth to a particular shape. The saw filer uses a semi or fully automatic grinding machine for this. Saw bands 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 saw band gullets. Resaw Bandsaws (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 profile of the tooth (including gullet area, hook angle and top clearance angle) 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 saw filer will maintain the gullet shape by manually shaping the grinding wheel with a dressing stone, 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 bandsaw 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.
Fitting means tooth dressing and involves swaging, shaping, gauging, and grinding. The tip of the saw tooth is swaged to a flare, then the sides are compressed in slightly with a shaper tool to an exact kerf. Then a final grinding pass is made. The usual gauged tolerance is +/- .005" in kerf, and < .003" side to side variation. The same grinding machinery used for gumming is used for fitting.
The saw kerf is usually made this way from the base saw metal. Sometimes, however, the kerf is made with stellite or carbide tips, in which case swaging and shaping isn't needed, although gumming is still required. The kerf may also be 'set' with a punch and hammer, with the teeth bent left, right, left... Set teeth are rarely used.
Benching is the leveling and tensioning of the saw. When a saw band is run on a mill it is stretched with force, and during operation the cutting edge heats up. These forces and temperatures could cause the saw to deform. Benching deforms an un-mounted saw in a way that counteracts the operating stresses.
Benching is done in a dark room with a stretcher-roller machine and flat anvil. A single light at the benchman’s work station, along with ground gauges, allows the saw filer to measure level and tension.
Leveling is done with a crossface hammer and stretcher-roller adjustments. Cross face hammers are available in left and right hand versions. Each filer has his own hammer which he carefully dresses.
Tensioning is done with the stretcher-roll. This machine has hardened rollers above and below the saw. They rotate slowly (one is powered, while one runs free) and pinch the saw when a lever is cranked, rolling a thin strip through the length of the saw, stretching the metal where it was rolled. Careful placement and force of the rolls deform the metal in a way that counteracts the forces the saw sees during operation. More rolls are placed in the midsection of the saw. Resaws have the back pulled to counteract the uneven heating of the cutting edge. This is done by rolling the back (non cutting edge) of the saw. The back is measured with a three pin gauge, and is usually around .003" per three feet curved.
Other bandsaw duties include welding broken teeth, fixing cracks, and trouble shooting lumber defects.
CNC equipment has evolved to the point of being able to do significant benching and fitting tasks without human monitoring.
Most of the above terms are North American and are called different things in Australia, New Zealand as well as elsewhere in the world. A saw filer does both the tasks of the benchman and filer at the same time, with no distinction between the tasks as well as having to do circular saws and bandsaws. This like filing rooms are called Saw Shops in Australia. Most Saw Mills in Australia and New Zealand run a stellite tipped bandsaw in which the majority of what is stated above becomes redundant as it is specifically for sharpening and making the swaged tipped saws.
Saw filers have the same maintenance duties with circular saws as they do with band saws, with a few exceptions;
A circular saw is a power-saw using a toothed or abrasive disc or blade to cut different materials using a rotary motion spinning around an arbor. A hole saw and ring saw also use a rotary motion but are different from a circular saw. Circular saws may also be loosely used for the blade itself. Circular saws were invented in the late 18th century and were in common use in sawmills in the United States by the middle of the 19th century.
A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge. It is used to cut through material, very often wood, though sometimes metal or stone. The cut is made by placing the toothed edge against the material and moving it forcefully forth and less vigorously back or continuously forward. This force may be applied by hand, or powered by steam, water, electricity or other power source. An abrasive saw has a powered circular blade designed to cut through metal or ceramic.
A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade and hobby tasks. Most are hand tools, made of a case hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted.
A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of sizes and tooth pitches, which enables the machine to be highly versatile and able to cut a wide variety of materials including wood, metal and plastic.
A hacksaw is a fine-toothed saw, originally and mainly made for cutting metal. The equivalent saw for cutting wood is usually called a bow saw.
A crosscut saw is any saw designed for cutting wood perpendicular to (across) the wood grain. Crosscut saws may be small or large, with small teeth close together for fine work like woodworking or large for coarse work like log bucking, and can be a hand tool or power tool.
A ripsaw is a wood saw that is specially designed for making a rip cut, a cut made parallel to the direction of the wood grain.
Swaging is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process, but also may be hot worked.
A miter saw or mitre saw is a saw used to make accurate crosscuts and miters in a workpiece by positioning a mounted blade onto a board. A miter saw in its earliest form was composed of a back saw in a miter box, but in modern implementation consists of a powered circular saw that can be positioned at a variety of angles and lowered onto a board positioned against a backstop called the fence.
A backsaw is any hand saw which has a stiffening rib on the edge opposite the cutting edge, enabling better control and more precise cutting than with other types of saws. Backsaws are normally used in woodworking for precise work, such as cutting dovetails, mitres, or tenons in cabinetry and joinery. Because of the stiffening rib, backsaws are limited in the depth to which they can cut. Backsaws usually have relatively closely spaced teeth, often with little or no set.
Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations. They remove material by their movement within the machine or directly from the cutter's shape.
A scroll saw is a small electric or pedal-operated saw used to cut intricate curves in wood, metal, or other materials. The fineness of its blade allows it to cut more delicately than a power jigsaw, and more easily than a hand coping saw or fretsaw. Like those tools, it is capable of creating curves with edges, by pivoting its table.
A vise or vice is a mechanical apparatus used to secure an object to allow work to be performed on it. Vises have two parallel jaws, one fixed and the other movable, threaded in and out by a screw and lever.
A saw set is a tool or part of the tool kit for tuning saw blades. It adjusts the set, or distance the saw tooth is bent away from the saw blade. The magnitude of set determines the cut width and prevents the blade of the saw from binding in the wood.
In the context of machining, a cutting tool or cutter is typically a hardened metal tool that is used to cut, shape, and remove material from a workpiece by means of machining tools as well as abrasive tools by way of shear deformation. The majority of these tools are designed exclusively for metals.
This glossary of woodworking lists a number of specialized terms and concepts used in woodworking, carpentry, and related disciplines.
A riving knife is a safety device installed on a table saw, circular saw, or radial arm saw used for woodworking. Attached to the saw's arbor, it is fixed relative to the blade and moves with it as blade depth is adjusted.
The saw chain, or cutting chain, is a key component of a chainsaw. It consists of steel links held together by rivets, and superficially resembles the bicycle-style roller chain, although it is closer in design to a leaf chain. Its key differences are sharp cutting teeth on the outside of the chain loop, and flat drive links on the inside, to retain the chain on the saw's bar and allow propulsion by the engine or motor.
A jigsaw is a saw which uses a reciprocating blade to cut irregular curves, such as stenciled designs, in wood, metal, or other materials.
The M. K. Morse Company is a global manufacturer of saw blades and power tool accessories. M. K. Morse sells products in 70 countries.