A
radial arm saw is a cutting machine consisting of a
circular sawThe circular saw is a machine using a toothed metal cutting disc or blade. The term is also loosely used for the blade itself. The blade is a tool for cutting wood or other materials and may be hand-held or table-mounted. It can also be used to make narrow slots...
mounted on a sliding horizontal arm. Invented by
Raymond De WaltRaymond E. DeWalt invented the radial arm saw in 1922. In 1924, he founded DeWALT Products Company in Leola, Pennsylvania, to manufacture and sell the “Wonder-Worker” .DeWALT, Inc is now a subsidiary of Black & Decker....
in 1922, the radial arm saw was the primary tool used for cutting long pieces of stock to length until the introduction of the
miter sawA miter saw is a saw used to make accurate crosscuts and miters in a workpiece.-Manual miter saw:The basic miter saw is the manual miter saw. It is a saw suspended on rollers in a metal guide that works with a miter box that allows making accurate crosscuts and miter cuts...
in the 1970s.
In addition to making length cuts a radial arm saw may be configured with a dado blade to create cuts for
dadoA dado , housing or trench is a slot or trench cut into the surface of a piece of machinable material, usually wood. When viewed in cross-section, a dado has three sides...
,
rabbetA rabbet is a recess or groove cut into the edge of a piece of machineable material, usually wood. When viewed in cross-section, a rabbet is two-sided and open to the edge or end of the surface into which it is cut....
or half lap joints. In addition some radial arm saws allow the blade to be turned parallel to the back fence allowing a
rip cutIn woodworking, a rip cut is a cut made parallel to the wood grain. Rip cuts are commonly made with a table saw, but other types of saws can also be used, including hand rip saws, radial arm saws and band saws...
to be performed.
Origins
Unlike most types of woodworking machinery, the radial arm saw has a clear genesis: it was invented by
Raymond De WaltRaymond E. DeWalt invented the radial arm saw in 1922. In 1924, he founded DeWALT Products Company in Leola, Pennsylvania, to manufacture and sell the “Wonder-Worker” .DeWALT, Inc is now a subsidiary of Black & Decker....
of
Bridgeton, New JerseyBridgeton is a city in Cumberland County, New Jersey, United States, in the south part of the state, on the Cohansey River, near Delaware Bay. As of the 2010 United States Census, the city population was 25,349. It is the county seat of Cumberland County...
. De Walt applied for
patentA patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
s in 1923, which were issued in 1925. De Walt and others subsequently patented many variations on the original, but De Walt's original design (sold under the moniker
Wonder Worker) remained the most successful: a circular saw blade directly driven by an
electric motorAn electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
held in a
yokeA yoke is a wooden beam, normally used between a pair of oxen or other animals to enable them to pull together on a load when working in pairs, as oxen usually do; some yokes are fitted to individual animals. There are several types of yoke, used in different cultures, and for different types of oxen...
sliding along a horizontal arm that is some distance above a horizontal table surface. A saw which combines the sliding and compound features is known as a
sliding compound miter saw or
SCMS.
Before the advent of the radial arm saw,
table sawA table saw or sawbench is a woodworking tool consisting of a circular saw blade, mounted on an arbor, that is driven by an electric motor...
s and
hand sawIn woodworking and carpentry, hand saws, also known as "panel saws", "fish saws", are used to cut pieces of wood into different shapes. This is usually done in order to join the pieces together and create a wooden object. They usually operate by having a series of sharp points of some substance...
s were most commonly used for crosscutting
lumberLumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....
. Table saws can easily rip
stockStock is a representation of capital paid or invested into a business entity.Stock may also refer to:-Places:* Stock, Essex, England* Stock, Podlaskie Voivodeship, Poland* Stock Township, Harrison County, Ohio, United States...
, but it is awkward to push a long piece of stock widthwise through a table saw
bladeA blade is that portion of a tool, weapon, or machine with a cutting edge and/or a pointed tip that is designed to cut and/or puncture, stab, slash, chop, slice, thrust, or scrape animate or inanimate surfaces or materials...
. In contrast, when a radial arm saw is used for crosscutting, the stock remains stationary on the saw's table, and the blade is pulled through the stock.
Beginning about the late 1970s, the compound
miter sawA miter saw is a saw used to make accurate crosscuts and miters in a workpiece.-Manual miter saw:The basic miter saw is the manual miter saw. It is a saw suspended on rollers in a metal guide that works with a miter box that allows making accurate crosscuts and miter cuts...
began to replace the radial arm saw somewhat, but only for crosscuts and miter cuts since miter saws are unable to perform rip cuts. The radial arm saw can be less safe when used by an inexperienced or untrained operator, but is not dangerous when used properly. In the hands of an experienced operator, the radial arm saw can safely cut compound miters necessary for picture and door frames, rip lumber precisely to width, cut tongues and grooves, and make variable dadoes. Most cuts are followed with a fit and require more material be removed, sometimes a tiny amount (which is easy to do). Like the compound mitre saw, the radial arm saw can make these cuts with absolute precision, but is capable of making a wider variety of cuts, including more complex ones.
In the home shop the radial arm saw is an alternative to the table saw. Both machines can rip, crosscut, do simple and compound miters, dado, mold or shape, make tenons, make open mortises, taper cut, and rabbet. The radial arm saw requires less clearance or space in the shop to handle long stock. An arm saw only requires clearance on the sides, whereas a table saw needs clearance to the sides, in front, and in back. The arm saw is perfectly efficient backed up against a wall, whereas the table saw wants to be placed in the center of the shop to give all around clearance. With some accessories the radial arm saw can be used as a shaper, a disk or drum sander, a grinder, a surface planer, a router, a horizontal boring machine and even as a power unit for a lathe; whereas a table saw's secondary uses are limited to shaper and disk sander. The major shortcoming of most current radial arm saws for home-use is that most radial arm saws that have been built after the early 1960s are manufactured with stamped sheetmetal parts and are machined to loose tolerances, and hence, they are not precise for doing accurate work without 'tuning'. A high-quality radial arm saw has carefully machined trackarm ways and locking mechanisms, and a motor that runs very smoothly; under 'no-load' conditions most of the sound and vibration will originate from the whisper/whistling and the imbalance of the sawblade upon the arbor.
Safety
Radial arm saws require a blade with a very low or negative hook angle, to inhibit overly fast feed rate, binding, and the blade's tendency to try to
climb the material.
Also a 10 deg. positive hook blade with a "triple chip profile" works well on the radial arm saw and can be considered a universal blade. If the saw climbs with this blade the yoke roller bearings need to be adjusted and tightened.