Glossary: Radial Arm Saw

A saw -- with the blade and motor mounted on a track, above the work surface -- used primarily for Crosscutting and Dadoing, i.e., cutting Grooves across a board's Grain.

Now largely replaced by the Compound Miter Saw, a saw in group of saw models often characterized as "Chop Saw", the RAS still has a cadre of supporters, from the ranks of "old tool enthusiasts", such as the Old Woodworking Machines web-based group.


Dewalt RAS History 1920s - 1990s

First, a little bit about radial arm saws.

The radial arm saw (RAS) stands out in stark contrast with the more widely used "table saw".

The reason for this contrast between these two tools is how differently they operate: for the table saw, the operation consists of workpieces cut by moving them over the rotating blade; for the RAS, the operation consists of workpieces cut by pulling the rotating blade over the workpiece, which makes the cutting operation fully visible to the operator.

The Many Operations Possible With the Radial Arm Saw

Dadoing, in particular, is one operation that separates this saw from its competitors, especially the Tablesaw. In Dadoing with any saw, such as a Tablesaw, where the Blade extends upward from below the Table, the Dadoing operation necessarily is completed on the bottom-side of the workpiece, out of sight of the woodworker. Not so with the RAS. In Dadoing with a RAS, the workpiece sits motionless under the motor and blade, where -- as the blade cuts the Dado -- the action is in full sight of the RAS operator. These and other operations in woodworking are featured in a 1930 article by Klenke.

The RAS suffers from a "bad rap"

(I am indebted to Roger A Hill's pdf for these items.) This bad rap focuses primarily on two issues: first, that because of inadequate training by distributors and salesmen, the radial arm saws purchased by consumers were never set up properly, implying, sadly, that never were the RAS used in the ways for which they are designed.

Second, the radial arm saw developed an undeserved reputation as unsafe; today, the saw continues to be grossly under-appreciated and much maligned. (However, I have a strong reseveration to Wallace Kunkel's claim that the RAS is safe for rip cuts. The RAS is not safe for rips cuts; and, for me, this is one place where the table saw is the only choice.)

The Concept of a Tilting Arbor

The invention of the radial arm saw heralded a variation the concept of a tilting arbor. (Tilting arbors have been used in table saws since around 1910.) Sometimes simply called "radial saw," it's a saw with the blade and motor mounted above the work surface and used primarily for crosscutting and dadoing. Today, it is largely replaced by the Compound Miter Saw. Many owners, if they have the space, continue to use this saw, though, because it excels at dadoing.

dewalt patent 1
ray dewalt 1920s RAS

Patents held by E. J. Fager (March 20, 1923, 1,449,3170 and Raymond DeWalt (March 03, 1925, 1,528,535, and so forth)

Patents held by Dewalt tools:

Using the browser, Internet Explorer, click on the link below for the Patent record on DatAmp:

Who Put the "Radial" In Radial Arm Saw?

In submitting their patents, neither E. J Fager, nor Ray Dewalt (patent # 1,528,535) for the saw in 1925, used the term "radial", but instead used "rotatable".

Maybe this image answers the rhetorical question above. The image comes from the 1929 catalog, "Wordworkers Tool Works", a Chicago-based distributor:
j d wallace

Until I found this catalog entry, my searches indicated that, as a label for the RAS, "radial" did not appear until the 1940s -- please note: this is not rocket science. My searches of the Newspaper Archives database shows no hits before 1940, then -- between 1940-1950, 136, all in classified ads in the newspapers digitized by the Newspaper Archives database. The first "hit" in the New York Times is Oct 7, 1956, and in the retrospective Reader's Guide to Periodical Literature, the first occurrence seems to be 1953. Have yet to search my files of Home Craftsman magazine and am just about to start looking at volumes of Popular Homecraft.

Table-Saw vs Radial-Arm Saw

What is more interesting about the appearance of the radial arm saw in the 1920s is that evidently it was not seen as a "tilting arbor" circular saw, as in Table-Saw. Why? Maybe because observers detected that the operations of each type of saw are different in a vital way: on the Table Saw, the wood is pushed into the blade, -- from the infeed table to the outfeed table -- with the cutting operation taking place on the under side of the wood, out of the operator's sight; on the RAS, the wood remains unmoving while the motor and the rotating blade moves across it, in full view of the RAS operator. This is all speculative, of course, but I would like to know a little more, just to learn what sort of thinking -- if any -- occurred on this topic.)

Below I have posted Wallace Kunkel's hyperbolic rant about the RAS "superiority" over the Table-Saw. (I selected the phrase "hyperbolic rant" intentionally, of course, not because I dispute Kunkel's claims -- no, his claims are solid -- but because of Kunkel's inclination to exaggerate by putting words in UPPER CASE LETTERS and by using bold text, thinking that without this sort of emphasis, the reader will fail to understand the intensity of his passion for championing the RAS.

Table-saw vs. Radial-Arm saw.

Almost anybody can operate a table-saw because he understands one thing: HE will have to PUSH the board for every cut he makes.

This also means that he is completely responsible for the results he gets. If his cross-cuts are a little off-square or his miters have a little gap between them, he has no one to blame but himself! The machine, of course, could have done it perfectly — if only he were more professional.

And he accepts that as a fact.

Not so with a radial-saw. That machine is always assumed to be at fault — never the operator. Oddly enough, this is not far from the truth. But the real truth is that the operator knows too little about his machine. And, over the past 30 years (specifically, since Black and Decker bought it), there were too few places for him to go for knowledgeable help.

Long gone are the days when machine and tool manufacturers vied for position and acceptance in front of the public — in an actual win-or-lose struggle. Virtually gone is the dealer who can professionally demonstrate a radial-saw (even a table saw!), professionally align it, and guide the customer toward the satisfaction for which he is paying. Equally unfortunate is the fact that over 20 different makes of radial-saws have come and gone (or should go!) — each one sucking up little or large portions of the market — and few of them deserving of a crumb.

Source: Wallace Kunkel, How to Master the Radial Arm Saw. page 24.

For "first" tilting arbor patent, see Tilting Arbor/Tilting Table in Glossary T. In 1906, the Oliver Mitre saw, a model using a direct-drive motor, introduced a tilting arbor mechanism. In 1927, J D Wallace introduced a table saw for the home-shop market with a tilting arbor.

link to adv for delta multiplex RAS 1950

From my research on the presentation of the RAS to the quickly growing ranks amateur woodworkers and do-it-yourself homeowners in the post WW II era, it looks like the January-February, 1950, article in the Home Craftsman, where an aging Herman Hjorth -- one of the grand old men of the hey day of the Industrial Arts era -- was the first major disclosure. See the text and some images of the article here.

(Sometime in the 1970s, I bought my first RAS, a second-hand a 1950s 10" "delta multiplex", for $200.00. Scrawled in red crayon, on the top of the movable second arm, is the price charged by Bellingham Hardware: $240.)

For the table saw, the results of a cut remain unseen until the operation is complete and the workpiece turned over for inspection. For each tool, the range of cutting operations includes dadoes, molding, and rabbeting, The RAS is capable of boring, mortising, routing/shaping, sanding, grinding, buffing, and -- with an accessory -- operating as a saber-saw. For more on RAS capabilities, click on link in box below:

Document # 46: The Radial Arm Saw: "Machine Sawing From On Top" In the shaded box on the linked page, Mr William W. Klenke describes the DeWalt radial arm saw, Model JR, that was released on the market in 1929. In length, the article is a mere two pages, but it describes how -- using a new type of saw and shaper -- someone can build a "built-in Colonial corner closet".

(The author of the article, William H. Klenke, was an instructor of shopwork in the Central Manual Training High School, Newark, N. J., a practicing architect, and the author of Selected Furniture Drawings and many other books on craftwork.)

For brief background on the development of the radial arm saw in the 1920s, particularly the role of Ray DeWalt's contributions, click here: Appendix 18: On the Origin of the Radial Arm Saw

RAS History

In the mid-1920s it was introduced as a production machine in the woodworking industry. Its entrance into the arena of amateur woodworking was later: post WW II, but it prevailed as a major machine tool of choice only for a few decades. Today its primary function -- as a cut-off saw -- is largely replaced by the sliding compound miter saw.

Raymond E. DeWalt invented the radial arm saw in 1922. His company, DeWalt, produced the original model -- Wonder Worker -- for several years. In the mid to late 1930s, the design was modified to include four major innovations:

  1. A strong cast iron arm
  2. A rollerhead with four bearings
  3. A one-piece, double-sided cast aluminum motor to maximize the available depth of cross-cut, a flat-bottomed motor

The heft of the cast iron arm necessitated that the support column and base also be very hefty, just to support the arm. (The image below fails to illustrate the shear heft of these tools.)

The saw was built and sold in many different sizes over the years, ranging from the 1/2 h.p. MMB 8” model to the 36” Timber Cutter TC12. (Wally Kunkel describes these models in his book.)

On these old DeWalts, all of the arm and base castings were aged, and then precisely machined to very close tolerances. The ancillary parts, such as clamp arms, scales and the original tables were of similar high quality.

In the 1930s and 1940s, for beginners to RAS, DeWalt employed craftsmen -- experts skilled in using the RAS -- to offer hands-on-training and demonstrate its tools. Around the 1960s, these teachers disappeared, marking the end of the era of training of beginners to use RAS.

In 1948, DeWalt sold the entire operation to American Machine and Foundry Company (AMF). Under the AMF DeWalt name, AMF continued to produce the radial saw line to the same high standards.

In 1948, AMF DeWalt began marketing directly to the amateur woodworker. The company employed hands-on craftsmen like Wallace Kunkel to demonstrate Dewalt's smaller saws at home shows, local hardware stores, and even on television. Wallace Kunkel's How to Master the Radial Arm Saw is testimony to the short reign of the RAS. Kunkel worked for American Machine and Foundry (AMF) from 1948 to 1960, and was one of the craftsmen who demonstrated AMF DeWalt radial arm saws to new users, and provided hands on training to beginners.

Rockwell-Delta built their high quality 10” saw with a center pivot two piece arm, but due to high manufacturing costs, this saw was not really geared to the DIY market. (I have one of these saws.)

(See Herman Hjorth's 1950 article on the RAS in the Home Craftsman magazine.)

In 1960, Black and Decker bought AMF Dewalt. From the acquisition in 1960, until about 1965, Black and Decker continued to produce solid cast arm saws at the Lancaster, PA plant.

Black and Decker was geared to market to consumers through outlets. They also sold consumer saws through Sears and Roebuck and Montgomery Ward, which had no staffs for demonstration and training.

During the 1960s, competition drove two things: reduced price and reduced quality. Sears dropped Black and Decker and sold a cheaper saw built by Emerson Electric.

Black and Decker -- in the wake of losing their share the consumer market to Sears and Montgomery Ward -- proceeded with significant design changes in their consumer-grade saws. To emulate the Sears design, Black and Decker moved the raising-and-lowering crank from the top of the post to below the table, which put the crank between the operator and the saw. As Roger Hill notes, for customers, this design change was a “safety feature” because it allowed adjusting the level of the motor/blade without the necessity of reaching behind. On the lower priced models, Black and Decker cheapened the overall construction by changing the motor, yoke and clamp design.

Basically, the reduction in quality showed in every part of the saw. I have heard it characterized by someone, once, as "a rush to the bottom".

While Black and Decker did continue to build solid-arm saws, but -- because they were a much higher priced -- these machines sold primarily to the contractor, lumber yard, and other rough-wood dimensioning outlets.

Black and Decker also changed the motor ratings. Horsepower was rated as "developed" h.p. This is the peak horsepower a motor develops just before the circuit breaker trips from overload. A 1-1/2 h.p. motor from a 1030K might have been capable of 3 “developed” h.p., but it would be the same 1 Y2 h.p. 17 amp. motor. They also put 10” and 12” blades on the underpowered saws.

Finally in 1990 Black and Decker stopped manufacturing the DeWalt radial arm saw. They kept the name DeWalt, but sold the entire radial arm operation to Lancaster Saw Company. A year or so later, Lancaster went bankrupt, and the large arm and yoke casting patterns were acquired by The Original Saw Company of Britt, Iowa. Original Saw continues to produce high quality, round-top arm radial saws in the larger sizes, identical to the old DeWalts, but they have never built up a line of robust consumer saws like the old MDFs, GWs, 925Hs or 1030Ks.

Sears now produces their radial arm saws in China and Emerson builds the RIDGID line sold by Home Depot. Delta makes a smaller 10” consumer saw with a single cast iron arm. By comparison, considering the low quality of the modern consumer-grade saws, and for the price, a person would be much better served by hunting down an old DeWalt and/or Delta RAS, and reconditioning it.

The professional woodworker and sometime editor of and contributor to woodworking magazines, Sandor Nagyszalanczy, captures well the origin, the impact, and decline of the Rad1al Arm Saw:

Radial-arm saws have gradually been replaced by the portable and easier to use (and often more accurate) cutoff saws [general called sliding compound miter saws].

The radial-arm saws—as well as the contemporary cutoff saws that have followed them—are based on the same idea: that the work remain stationary while the sawblade moves over and through it.

It's an idea for cutting wood that predates even the radial-arm saw. Early crosscutting saws, with names like the Vertical Column-Bracket Cutting-Off Saw and the Over-Hung Traversing Gainer and Cut-Off Saw were cast-iron monsters with huge, unprotected circular sawblades that cut well, but the saws were expensive to build and very dangerous to use.

Raymond DeWalt is popularly credited with the invention of the radial-arm saw (woodshop veterans often call their radials "DeWalts").

His machine suspended a bladed motor carriage on a yoke, which slid along a long horizontal arm.

The yoke allowed the head to tilt for bevel cuts and to swivel for ripcuts. Mounting the arm to a pivoting column allowed miter cuts, and raising and lowering the column changed the blade's depth of cut.

He built his first production model, the Universal Woodworker, in 1924, the year he established the DeWalt Products Co.

The basic DeWalt design has changed little over the years. But don't think that radial-arm saws are extinct. This example—and thousands of others are still in daily use in garage shops, professional cabinet shops, and industrial factories all over the world.

Source: Sandor Nagyszalanczy Power Tools: An Electrifying Celebration and Grounded Guide Newtown, CT: Taunton Press, 2001, page 63.

In 1956, Delta's Getting the most out of your Radial Arm Saw Pittsburgh: Rockwell Manufacturing Co., 1956 was issued, and after uploading the pdf on your computer's hard-drive, you can read it.

Also issued in 1956, this time by the mainline publisher, McGraw-Hill, was Robert Scharff's manual -- Easy Ways to Expert Woodworking dedicated entirely to the Dewalt radial-arm saw -- the Dewalt Power Shop -- and marketed exclusively for he saw's owners in home workshops.

That a mainline publisher -- such as McGraw-Hill -- is publishing a book on the radial arm saw indicates that corporate America projects "big time" for a market made up of amateur woodworkers. Checking out the Table of Contents for the Scharff volume (click here) and the Table of Contents Delta volume (pdf above) gives you the conviction that the two authors sat side-by-side as each wrote his respective manual.

CHAPTER 1: Introduction to the radial-arm machine

WOODWORKING is the most lasting and also the most satisfying of all pastimes. This fact can be borne out by the ever-increasing popularity of this hobby. One of the most powerful appeals of wood to all workers is the ease with which it can be fashioned into useful products. It can be cut into any desired form and shaped, drilled, or sanded; as a matter of fact, it can be worked with a variety of wood-working tools.

Wood is also very flexible in application. It can be used in many different ways to produce many different items; in fact, there are over 6,000 known uses of wood, ranging from a toothpick to a structural member in an industrial building. The flexibility of wood and its ease of working have led to the development of versatile tools of many different designs and types, each of which enjoys one or more features to satisfy a specific need.

When selecting a power tool for your shop, the determining factor is not so much the many jobs it can do but primarily the end uses, that is, how it fits your particular needs. The tool that meets this requirement, yet is extremely versatile, is the radial-arm machine. Homecraftsmen and hobbyists are discovering that theycan get professional scope and skill into their work with this machine.

As you can see by the table of contents, it is a complete workshop. It will saw, dado, and shape with complete ac-curacy. (These operations comprise basically 85 per cent of all homeshop work.) With the proper attachments added, it will function as a jointer, drill press, router, saber saw, lathe, sander (disk, belt, and drum), grinder, buffer, and polisher.

Principle of Operation.

The radial-arm type of power tool is in effect a mechanical arm that features the easy dexterity of a human arm. In fact, it can actually duplicate all movements with unerring, controlled accuracy on every operation. When cutting lumber, for instance, the human element makes it impossible for even an expert carpenter to cut two boards exactly alike; but the mechanical arm, with its ball-bearing carriage riding on precision-machined tracks, guarantees accuracy on every cut. For further ac-curacy and safety, all work is done from the top of the material.

Flexibility with this tool means that the cutting member can be placed in any position throughout all three dimensions (length, width, and depth).

This is possible because of the unique design allowing full maneuverability through a complete circle in any of three directions. Without going into the why's and wherefore's of these different movements (they will be explained in detail in Chapter 2), let us see how three-dimension flexibility is possible with the motorized mechanical arm....

Source: Robert Scharff, Easy Ways to Expert Woodworking. New York: McGraw-Hill, 1956, pages 1-2.

1947 dewalt RAS

Generally recognized as the leading champion of the radial arm saw, specifically the Dewalt radial arm saw, Wallace Kunkel, extols the usefulness of radial arm saws in his 1997 ring-bound book, How to Master the Radial Saw.

delta double-arm radial 1950s

(Since I myself am definitely not an "expert" on the RAS, like, say Wally Kunkel, nonetheless I respect and treasure these machines. I have two vintage machines: an 1943 Dewalt GP -- it's a 12-incher with a 2-hp (old rating) 220 volt motor -- and an early 1950s vintage Delta "double-arm" 1 and 1/2 hp (old rating)

The diagram above on the left illustrates the features -- especially the "double arm" -- of my Delta. This image is from Delta's Getting the most out of your Radial Arm Saw (Pittsburgh: Rockwell Manufacturing Co., 1956.

The text below is from an Old Woodworking Machines pdf of the manual for the Powr-Kraft RAS:

This saw is equipped with two auxiliary power spindles. They operate at 3450 and 10,000 R.P.M. to give maximum flexibility with attachments. Speeds and direction of rotation are indicated on the casting. Each of these spindles is intended for the use of certain accessories. The 10,000 RPM Spindle has a 15/32" - 20 thread, and the 3450 RPM Spindle has a 1/2"-20 thread.

10.000 R.P.M. SPINDLE

The 10,000 R.P.M. Spindle is intended for routing and shaping use. Routing is normally done with the motor in a vertical position, but other positions can be used. The routing bit is mounted in the collet that is provided. Best performance of the router bit will be obtained if as much as possible of the shank is inserted in the collet. Adjust the routing bit so that about 1/2" of material is removed at a time until desired depth is obtained.

Routing may be done either by moving work with the router bit held in position or clamping the work and moving the router.

The shaper cutter is mounted on the special adapter that is provided, and is used on the 10,000 R.P.M. spindle.

The adapter package contains detailed instructions on the use of the shaper. Routing cutter. Adjust the cutter so that 1/8" of material is removed at a time until desired depth is obtained.

(Note: I am indebted to Rick Antrobus for comments on this piece.)

Sources: Herman Hjorth, "How to Operate Your Power Tools: The Radial Arm Saw" Home Craftsman 19 January-February 1950, pages 18-20; Hjorth wrote several articles for HC, and later, HC published these same article in book format, but under the authorship of Milton Gunerman. (Robert Scharff, Easy Ways to Expert Woodworking New York: McGraw-Hill, 1956; Delta's Getting the most out of your Radial Arm Saw (Pittsburgh: Rockwell Manufacturing Co., 1956; Wallace Kunkel, How to Master the Radial Arm Saw (citation not complete: privately printed with a Xerox machine, the book lacks info on both publisher and publishing date-- now out of print, Kunkel's book champions the industrial-level Dewalt RAS domesticated for home shops in the later part of the 1940s). R. J. DeCristoforo, The Magic of Your Radial Arm Saw New Ringgold, Pa.: Scharff Associates, 1983. 309 p. Roger W. Cliffe, Radial Saw Techniques New York: Sterling, 1986; Jon Eakes, Fine Tuning Your Radial Arm Saw Toronto?: Lee Valley Tools Ltd., 1987 (The Eakes book -- electronically republished in 2000 by Interface Productions -- is available for download from The Editorial Board of DeWalt, Newest Ways to Expert Woodworking New York: Crown Publishers, Inc.,1962; Roger A. Hill, "Some Tips on DeWalt Radial Arms Saw Reconditioning " n.d..