Glossary Intro and Glossary Annexes

Steel Square; also known as "Carpenter's Square"

... [T]he Oxford English Dictionary defines the "carpenter's square" as, "a. An implement or tool for determining, measuring, or setting out right angles, or for testing the exactness of artificers' work, usually consisting of two pieces or arms set at right angles to each other, but sometimes with the arms or sides hinged or pivoted so as to measure any angle; esp. one used by carpenters or joiners. Freq. without article in phrase by square. Also fig. bevel-, mitre-, set-, T- or tee-, trial- or try-square". In the end, though, the dictionary does address matters associated with a steel square....

Writing in Fine Woodwworking, Chris Gochur says,

Although generally viewed as a carpenter's tool, it is extremely useful in the woodshop. Made from one piece of aluminum or steel, roughly 1/8 in. thick, with one arm 16 in. and the other to 24 in., it serves as a jumbo try square for larger work.

Among other tasks, I use mine to lay out cut lines on panels or wide lumber, to define joinery across wide case pieces, to test the corners of panels to verify accuracy, and to check case assemblies for squareness during glue-ups.

Although framing squares are not expensive and generally are not viewed as precision tools, I've used the same one for 20 years and have never had to true it up. I treat it with care, and like an old friend, it has never let me down.

Source: Chris Gochnour, "Eleven Essential Measuring and Marking Tools", Fine WoodworkingIssue 182 Janurary-February 2006, page 75.

click here for pdf of Albert Fair, The Steel Square as a Calculating Machine 1906.


An essential tool in woodworking, a "square" is used to check the accuracy of 90-degree angles and for layout work on a workpiece. Its name comes from its shape - two cuts that are made at a perfect 90-degree angle to each other are said to be square. This tool has two members -- the Blade and the Tongue -- that are joined together at a perfect 90-degree angle.

(The family of squares includes the carpenter's square, the try-square, the combination square, and several bevel-type squares. For accurate layout work, having at least one, and sometimes all, is required .)

Alternatively known as a steel square, rafter, or framing square -- the distinctions come from special markings on the square's surface -- this square functions on the principle of the right-angle triangle.

While variations exist on a square's tables and markings, the method of marking angles remains almost consistent over time. The longer blade is 24 in (610 mm) and the shorter tongue, l6in (407 mm).

On one side both blade and tongue are divided into sixteenths of an inch at the outer edge, and into eighths of an at the inner edge.

On the reverse side, the outer edges are marked in twelfths of an inch, the inner edge of the blade into thirty-seconds of an inch, and the inner edge of the tongue into tenthsof an inch. Special scales are located in the center of a square's broad surface.

Source of above: Adapted from Vic Taylor Woodworker's Dictionary Hemel, Hempstead, England: Argus Books, 1987, page 204.

Historic Documentation of the Carpenter's Square

According to The Barnhart Dictionary of Etymology, square comes from Old French esquire, esquarre, esquerre, and is used in the English language as early as 1250, as term for a "tool for measuring right angles".

1440 Promptorium Parvulorum page 704

Squyre, a carpenter's rule. (Complete PP entry below.)

1400 definition of square.jpg

1683 Joseph Moxon seems to be the first British writer to document "carpenter's square" with an actual image. Moxon ... Mechanick Exercises on the Whole Art of Printing.

The text on the "square" in the image on the left is on page 79 of Moxon, but -- for a contemporary rendering of a 1683 "square" -- the image below reproduces plate 4, page 69 of Moxon, which includes the illustation of 17th-century wooden square.

Moxon's 1683 description of

Moxon's 1683 description of

The Oxford English Dictionary 's definition of "carpenter's square" begins with a later source, an unpublished mss:

1688 R. Holme Acad. Armory iii. ix. 13

A Joyners Rule and a Carpenters Square.

The following account adapted from Wikipedia explains that Randle Holme's "Academy of Armory" [alternative sp. "Armorie"] was never published:

For centuries, Holme's writing remained as a manuscript, unpublished and available only to a select few with access, until 2000, when much of The Academie of Armorie was made available in 2000 on a CD produced by the British Library entitled "Living and Working in Seventeenth Century England: an Encyclopedia of Drawings and Descriptions from Randle Holme's Original Manuscripts for The Academy of Armory" (1688).]

Anne Wing, "CD Technology Brings New Life to Holme's "Academy of Armory" The Chronicle of the Early American Industries Association March 2000 , Inc.

1874 Edward Henry Knight, Knight's American Mechanical Dictionary: A Description of Tools, Instruments ... 1876, Volume 3, page 2293.

Square. 1. An implement used by artificers for laying off lines to which work is to be sawed or cut It consists essentially of two pieces at right angles to each other, one of which is sometimes pivoted, so that other angles than a right angle may be scribed or measured. ...

Carpenter's Squares With Impressed Figures Date Back To At Least 1800

Often called the "carpenter's square", "framing square","rafter square" or "roofing square". (The carpenter's square and the framing square both feature unique markings and tables, each designed for performing particular functions.

The early squares had no figures impressed on its surface, but beginning around 1800, evidence of metal squares with numbers and lines on are featured in woodworker's manuals in both England and America.

In the Carpenter's square both blade and tongue consists of an iron plate of one piece:

one leg is eighteen inches in length, numbered from the exterior angle, the bottom of the figures are adjacent to the interior edge of the square, and consequently their tops to the exterior edge;

the other leg is twelve inches in length, and numbered from the extremity towards the square angle.

A typical carpenter's square has four scales. One side is laid out with 1/8-inch gradations on one edge and ib -inch markings on the other. Flip the rule over and you have 1/32 -inch and 1/64 -inch gradations. Better machinist's rules also have engraved, or etched, markings; cheap rules have markings stamped on. You can find steel rules in some well-stocked hardware stores and always in machine tool supply houses.

Anatomy of the Steel Square

The construction of the carpenter's square is simple - nothing more than a piece of steel stamped in the shape of an "L." The steel it's made from is usually 1/8-inch thick. The longer, upright part of the "L" is called the body, while the shorter, bottom part is called the tongue. Standard models have a 24-inch-long, 2-inch-wide body, and a tongue that's 16 inches long and 1-1/2 inche body.


This type of square appears deceptively simpler to use than it actually is. Why? The scales impressed into the metal make using the square considerably more complicated, but for instances where ths steel square requires constant use, these scales are well worth the time required to get a command using them.

Ex: Use these scales to figure out "board measure" -- i.e., the amount of lumber needed for a woodworking project. Indeed, the multiplicity of tasks a steel square can perform has lead some author's of manuasl on the steel square to include "calculating machine" in the book's title: Albert Fair, The Steel Square as a Calculating Machine 1906.

Relatively inexpensive and virtually indestructible, steel squares are available in hardware stores, lumberyards, and major merchandising houses.

Review of Scholarship on the Steel Square

When you think about the introduction of the steel square -- especially when squares manufacture included the inches and fractions impressed on both sides -- about 1850, about the same time as the great bulge of housing construction got underway, the lack of scholarship on the steel square becomes puzzling. (OK, much the same thing may be said about other tools as well, such as role of the radial arm saw in the post-WW II housing boom, the "portable" machine tools developed by J D Wallace in the 1910s and 1920s, I suppose the list goes on and on, but -- considering the attention given by scholars to other topics of equal or lesser social value, the gap in scholarship is puzzling. [links needed] Reviewed as "scholarship" on the Steel Sqaure are E M Wyatt, Common Woodworking Tools, 1936, W L Goodman's 1964 The History of Woodworking Tools , R A Salaman Dictionary of Woodworking Tools, c. 1700-1979... (1975) , Paul B. Kebabian's rather brief, but incisive remarks in American Woodworking Tools, 1978, and U. L. Hiatt's master's thesis, The Steel Square: its Use Gunnison, CO: Western State College of Colorado, 1954.

In 1936, Edwin Wyatt perpetuates myths about Silas Hawes, although "probably" keeps the claim from completely tightening into a complete factual misrepresentation.

    ... The first metal squares made in the United States for the use of carpenters were probably made by Silas Hawes, a blacksmith of South Shaftsbury, Vermont, about the time that the War of 1812 closed. One day he welded some old pit-saw blades together to form squares, stamped scales on them and sold them to a peddler. This traveling merchant found such a ready market for the newfangled iron squares that he kept reordering, until within a year Blacksmith Hawes found himself manager of a square factory with several assistants. Hawes patented his metal squares, developed machinery for making them, organized several new factories... (page 51).

    Source: E M Wyatt, Common Woodworking Tools

Kebabian's study corrects many misunderstandings about the square's origins, and it from Kebabian that the following is adapted: Considering how common the steel square is in our society, its neglect by scholars is puzzling.

E M Wyatt's 1936 Common Woodworking Tools is the earliest scholarly study (found so far) of hand woodworking tools. Complete with bibliography of sources used, chapter-by-chapter, Wyatt traces the hand tools back to the Ancient world. Illustrated almost exclusively with pen-and-ink drawings, Wyatt precedes Goodman by a quarter of a century, but -- in comparison with Goodman, or Kebabian or Salaman -- suffers from a lack of scholarly rigor, a problem most likely caused by the state-of-the-art in woodworking history, especially archaeology, in the pre-World War II era.

The history of the steel square is an example of a gap in the scholarship of Wyatt's day, versus, say Goodman, or Kebabian or Salaman -- discussed below -- in a post-WW II era, when scholarly activities burgeoned on a remarkable scale.

(According to data in the Worldcat bibliographic database, Hiatt was born in 1888, meaning that in 1954 -- when he obtained his degree -- meaning that Hiatt was 66 years old.

First, getting your master's degree in your sixties is not that rare, but getting it at that age implies that you are fulfilling a lifelong wish to realize a personal dream, not launch a career, as master's degrees as a rule are designed to do.

My own career as a professional academic librarian began seven years later, in 1961.

The information scientist, Eugene Garfield, invented the citation index around that time, and in 1957, the sociologist Robert Merton introduced the notion of the bibliographic citation as the symbol for intellectual property, a theme that, with variations, was later developed by other writers. Click here for an article that covers this incident.

However, without the capacity of searching the literature of scholarship in digitized formats -- a capacity that is very common today -- these two revolutionary "theories" remained only theories, meaning that scholars of the 1950s -- working in the shadow of World War II -- still needed to conduct their research under the old conditons: slowly plowing through drawers of library card catalogs, paper periodical indexes, paper books and periodical articles, page by page, in search of the smoking gun evidence they needed to develop their arguments about the topic under investigation. (Rather than injecting the evidence that clinches my claim about the expansion of higher education since World War II-- it would bulk up a history of woodworking tools with an unnecessary overlay of studies on the rapid growth in scholarship throughout academe -- I will simply cite one study: The Academic Revolution, by Christopher and David Riesman, Edison, NJ: Transaction Publishers, 2002.)

W L Goodman's 1964 The History of Woodworking Tools -- probably considered either one of or the most authoritative study of the history of woodwrker's handtools -- is likewise very sketchy on the steel square: on page 200, are a scant two sentences by Goodman:

    In the Landesmuseum at Zurich there is an iron square from Neftenbach, consisting of three strips roughly 6 in., 8 in., and 10 in. long, welded together to form a right-angled triangle, with another strip at one corner making an angle of 45 degrees with the side carrying the stop. This must have been a very handy tool for setting out large timber-work or masonry. (page 200).

Uncharacteristically brief, R A Salaman's entry on the steel square -- Dictionary of Woodworking Tools, c. 1700-1979, and Tools of Allied Trades rev ed, London: Allen and Unwin, 1975, page 475 -- is not much more than a description of an 1822 image a book by Peter Nicholson, a prolific writer of books on architecture and related topics in London, circa 1800.

(I say "uncharacteristically" because -- as a rule, all tools discussed in Salaman's dictionary include an inspection of and references to existing scholarship on that particular tool.)

However, in Salaman's entry on the steel square something seems amiss, prompting the us of "uncharacteristic". Why? Because Salaman's entry on an early example of a metal prototype of the steel square shows an image of a "steel" square with markings for inches and fractions impressed on the blade and tongue, but the only accompanying text is the claim that it comes from the 1820s manual by Peter Nicholson, New Practical Builder.

To further confuse the situation, the book Salaman cites is online fulltext, but a search fails to turn up an image the square or a discussion of squares, suggesting that Salaman's reference to the image of that early steel square is erroneous.

Another view about the "first" metal square is proffered by Paul Kebabian's 1978 American Woodworking Tools. In Kebabian's case,

    Squares were indispensable, especially for laying out construction lines and checking right-angle joints. The joiner and cabinetmaker normally used small try squares with blades three to eighteen inches long, which they frequently fashioned themselves from choice pieces of mahogany.

    The manufactured joiner's square, with a steel blade and rosewood or ebony handle, brass trimmed, was appropriate for the craftsman who handled fine tools with care; for rough and ready use, it was also manufactured wholly in metal. House- and barn-builders' squares made from wood or iron often reached considerable size, with blades from six to eight feet long.

    The usual carpenter's square was blacksmith made in iron into the nineteenth century, or factory made in steel from 1820. The latter, with two-foot blade and fourteen- to eighteen-inch tongue, has many functions in building apart from its basic uses - marking right angles and measuring feet and inches. Boardmeasure can be calculated by the scale on the back of the blade.

    A version of this scale, known as the "Essex board measure," was developed by Jeremiah Essex, a nineteenth-century square-maker of North Bennington, Vermont. Another series of numbers constituting the "brace rule" is struck on the middle of the tongue. Various dimensions for two sides of a right triangle are given, and to the right of each pair of figures the length of the hypotenuse of that triangle is shown. This scale was used to measure lumber for diagonal braces in house, barn, or mill construction. Other scales were sometimes added to the square; one provided the measurement for the length of roof rafters at various pitches of the roof.

    Local Vermont tradition credits Silas Hawes of South Shaftsbury with the "invention" of the steel square in the early nineteenth century. He is said to have taken some old saw blades in payment for shoeing the horse of an itinerant peddler, and welded two of these together to make the first steel square.

    The story has charm, but is apocryphal; steel squares were known at least two hundred years earlier. (This part of the narrative is continued below.)

    Source: Paul B Kebabian, American Woodworking Tools Boston: New York Graphic Society, 1978, ch 9

The Square's Lineage

Inaccurately, the Greeks claim to be the inventors of the square. According to the Greek writer, Pliny, Theodorus, a Greek of Samos, invented the square and level. (Click here for a very sketchy bio on wikipedia.)

However, the Pyramids of Egypt plus some of the finest temples in Athens and other Grecian cities were built before Theodorus. Other evidence of the square are found in the ruins of pre-historic nations, and in the remains of ancient Herculaneum, Pompeii, Petra, Nineveh, Babylon, Etruria, and India.


The builders of Jerusalem, Greece, and Rome also used the square; the Romans called their square the Norma.

Source: Roger Bradley Ulrich, Roman Woodworking Yale, CT: Yale University Press, 2007page 55 According to archaeologists such as Flinders Petrie, historically, the (wooden) square dates back to the Ancient World, where a square was used by the Egyptians to build the pyramids, built probably about 3000 B.C. (Squares in the Egyptian Museum at Cairo are from the tomb of one Senutem at Deir el-Madina, and dates from the 14th century B.C.)

The Senutem wooden square was formed by two strips about 12 in. long, jointed at right angles, and carved with a hieroglyphic inscription. The Romans had several patterns of square, or norma, one similar to the Egyptian example, sometimes with a narrow strip along the shorter edge to act as a fence when setting out, and others made of flat pieces of board with a stop along one edge, some with a right angle cut out of the middle to mark out a mitre. In the Landesmuseum at Zurich there is an iron square from Neftenbach, consisting of three strips roughly 6 in., 8 in., and 10 in. long, welded together to form a right-angled triangle, with another strip at one corner making an angle of 45 degrees with the side carrying the stop. This must have been a very handy tool for setting out large timber-work or masonry.

Egypt, however -- considered the cradle of all the arts -- furnishes us with the most numerous and, likely, the most ancient evidence of the square used as a tool:

paintings and inscriptions on the rock-cut tombs,

the temples, and other works,

Themselves, the pyramids provide proof that the early Egyptians were familiar with some sort of instrument similar to our modern square.


In one instance, a cache of tools were discovered in a tomb at Thebes, where -- along with squares, on the left -- are mallets, hammers, bronze nails, some small tools, drills, hatchets, adzes, squares, chisels, etc. ; one bronze saw and one adze have the name of Thothmes III, of the 18th dynasty, stamped on their blades, which indicates that they trace back nearly 3,500 years. For more -- click here, and check note no 14.

South American antiquities in Brazil, Peru, and other parts of Central and South America show that natives of the so-called New World were familiar with many of the uses of the square.

Source: Adapted from Frederick Hodgson The Carpenter's Steel Square and Its Uses New York: Industrial Publication Co., 1883. (While I have suspicions about Hodgson's "authority" -- writing in 1883, when Anthropology was barely in its infancy, I am inclined to believe that the concept of the square in pre-Columbian Central America, especially around the Yucatan Peninsula, where the pyramids are still in existence today, and such a draw for tourists.

    W. M. Flinders Petrie,Tools and weapons illustrated by the Egyptian Collection in University college, London and 2,000 outlines from other sources. pl. 47 [60] (burial of Senedjem, Nineteenth Dynasty, Cairo 27259). A model from the tomb of Meketra is in the Metropolitan Museum of Art, New York (MMA 20.3.90, measuring 15.1 11.5 centimeters).

    For a model from a Twelfth Dynasty tomb at Nag' ed-Deir, see William K. Simpson, Papyrus Reisner II (Boston, 1965), frontispiece. See also J. E. Quibell and A. G. K. Hayter, Teti Pyramid, North Side: Excavations at Saqqara (Cairo, 1927), 41

Bridge From Ancient World to Middle Ages

During the Middle Ages, the square was a tool of several building crafts and trades. Its composition varied in form, size, and material, according to the needs and requirements of the specific trade and/or the intended use.

Blacksmiths, and -- sometimes -- stone and brick masons, used a metal square; but evidently the joiner and the carpenter used wooden squares, though of different sizes and forms.

The now familiar practice of marking the square with scales is apparently a recent innovation, as no such markings are found on drawings of old squares.

Squares of both Roman types were used throughout the Middle Ages, but as they were all made by the craftsmen themselves from suitable well-seasoned hardwood, usually old oak barrel staves, they vary somewhat in detail. The wide square for setting out is Nearly shown in the right-hand foreground of the Wierix title-page and also on a French carved shop sign one edge of the tool is square and the other at 45 degrees, while on the tankard lid of the mitre square is a separate tool. All these illustrations also give the L-shaped pattern for testing purposes. Felibien shows the equaire or plain square; the fausse equaire or bevel; the triangle quarre, a wide square for setting out; and the triangle angle, a mitre square similar to that on Fig. 156. Moxon remarks of both plain and mitre square that the handles are 1 in. thick and the blades 4 in., 'glewed and pinned' together.

Source: adapted from E L Wyatt, 1936;

The First Metal Squares

steel_square_nicholson_1845 Among the tools that belonged to Francis Eaton, the carpenter of Plymouth Plantation, was an iron square.

    Data comes from this genealogy website; see also this page

    Page 5 of Ken Horner's book on the steel square mentions that Eaton's estate includes a metal square, but no documentation is given.


    Francis Eaton was baptized in St. Thomas, Bristol, Gloucester, England in 1596, and came on the Mayflower at the age of 24, with his first wife Sarah and their "sucking child" Samuel. Sarah died the first winter, and Francis remarried to Dorothy (---), John Carver's maidservant. She died about two years later, and Francis married Christiana Penn about 1625 in Plymouth. Francis was a "house carpenter" by the age of 19, and is called a "carpenter" in the 1626 Bristol apprenticeship record and in his 1633 estate inventory.

    Francis died in 1633 in Plymouth, likely from a disease that was going around that year and also claimed Mayflower passenger Peter Browne.

    The inventory of Francis Eaton's estate included one cow and a calf, two hogs, fifty bushels of corn, a black suit, a white hat and a black hat, boots, saws, hammers, an adze, [metal?] square, augers, a chisel, boards, fishing lead, and some kitchen items.


    Neil D. Thompson, "The Origin and Parentage of Francis Eaton of the Mayflower," The American Genealogist 72(1997):301-309

    Lee Douglas van Antwerp, Mayflower Families for Five Generations: Francis Eaton, volume 1 (Plymouth: General Society of Mayflower Descendants, 1988).

    George Bowman, "Francis Eaton's Estate Inventory, The Mayflower Descendant 1(1899):198-199.

    ILL 10-16-08 William Bradford, Of Plymouth Plantation, ed. Samuel Morison (New York: Random House, 1952).

    Eugene Aubrey Stratton, Plymouth Colony: Its History and Its People, 1620-1691 (Ancestry Publishing: Salt Lake City, 1986).

When another Eaton, Governor Theophilus Eaton of New Haven, died in 1657, two iron squares were among his many tools.

Source: Paul B. Kebabian, American Woodworking Tools Boston: New York Graphic Society, 1978, page 188.
there were up to eight hundred fractional graduations on one side of the rule alone.

The original design of the machine marked only eighths of an inch, but it was soon improved to mark in sixteenths.

Following the death of some of the founders and sales of stock, the company changed hands.

It was incorporated in 1874 under a new management, capitalized at $60,000. From that date, with some lapses in lean years, the firm grew progressively and paid its owners an excellent return.

In 1916 the Stanley Rule and Level Company purchased the company, continuing the Eagle name and the South Shaftsbury location.

Today the Eagle Square Manufacturing Company, producing Stanley squares and other proprietary brands, has eighty-five percent of the world market for steel carpenter's squares, and produces one and a half million squares annually.

Illustrated by Peter Nicholson (London, 1822), a square made of iron, no. 5 on plate VII) with one leg 18 in long and the other 12 in.

Source: Peter Nicholson, The Mechanic's Companion: Or, The Elements and Practice of Carpentry, Joinery, Bricklaying, Masonry, Slating, Plastering, Painting, Smithing, and Turning ... and Containing a Full Description of the Tools Belonging to Each Branch of Business ... Also an Introduction to Practical Geometry London: W.C. Borradaile, 1831, page 42

An 1818 book, Circle of Mechanical Arts, by Thomas Martin shows a square (in figure 82) of the same dimensions as Nicholson claims, but gives no details about what it is made of. Nicholson's book is online, but a search discloses that there are neither text nore images relating to a square.)

Silas Hawes' Steel Square

wrong: The first metal square with figures was made about 1812 by Silas Hawes, a blacksmith of South Shaftsbury, Vermont.

In 1907 rafter-framing tables were added, the latest of the special markings to be put on the indispensable framing square.



Inventing the Mechanical Graduator

Silas Hawes received a patent on the carpenter's square from the United States Patent Office on December 15, 1819.

Unfortunately, because most of the patent records of the early nineteenth century were lost in fires, the features Hawes patented will probably never be known.

Early examples of Hawes squares, dated 1823 and 1826, include a board measure, and the flat blade and tongue were tapered.

Tapering improved the "hang" of the tool by making it more manageable in the carpenter's hands. Possibly one or both of these details were improvements on which the inventor was granted the patent.

South Shaftsbury, where Hawes started his business, became the country's steel-square manufacturing center during the nineteenth century.

Several local manufacturers made squares on the Hawes patent. Between January 1 and April 1, 1859, square-makers Dennis George, Jeremiah Essex, Herman Whipple, and the firm of Hawks, Loomis & Company joined forces to form the Eagle Square Company.

On a standard square,

on the face side, the inches are divided into various graduations, usually into eighths and sixteenths;

on the outside edge of the back (or reverse side), the inches are is divided into twelfths -- useful in making scaled layouts;

the inside edge is divided into thirty-seconds and one-tenths.


Their device mechanically stamped the graduations of the inch on the tools.

Prior to that time, every numeral, point, ruled line, and fractional demarcation of the inch was hand struck with dies and hammer;

(Click here for extensive account of the Eagle Square Company history and archive of its records.) The success of this new company was in no small measure attributable to their control of the "Millington graduator," a machine patented by Norman Millington and Dennis George on August 8, 1854.

millington_graduator_1868 Up to about the close of the Civil War, all metal squares were graduated by hand tools. In 1865, the still existing Eagle Square Manufacturing Company, located where Hawes started making his first squares, developed a mechanical graduator that stamped on the scale far more accurately and neatly than had before been possible by hand. About ten years later, machine stamping was extended to applying some of the special markings now found on the carpenter's framing square.

The square had originally been simply a tool for testing and laying out right angles. The addition of scales to the square greatly increased the possibilities of the tool. These made it possible to use the tool to lay out miters, special angles, ends of braces, figure rafter lengths, and gave many other uses to the square. Knowledge of how to use the square came to be looked upon as a measure of a builder's craftsmanship. Many pretentious books were written explaining how to use this tool. This accentuation of importance of the tool caused ingenious minds to devise many new markings to go on it. Even before the day of machine graduation, a Mr. Essex, then a foreman of the Eagle Square Manufacturing Company, had developed the Essex board-measure table. It is still one of the most 'valued markings on the framing square. The octagon scale, hundredth scale, and brace table were early and permanent developments. The rafter-framing table was the latest of the special markings. It appeared in 1907.

The recent improvements of the steel square have been the development of the take-down square, making one-piece squares without a weld at the angle, making its markings more legible, and development of rust-resisting finishes. The light aluminum square is one of the promising recent innovations. (pages 52-54).

    Square, Carpenter's (Roofing, Rafter or Framing Square) Fig. 692

    This is the traditional Square of the carpenter, and is used for setting out roofing, staircase, and other carpentry framing and certain millwright's work. Illustrated by P. Nicholson (London, 1822), it is made of iron with one leg 18 in long and the other 12 in. The figures number from the right-angled corner outwards and are graduated in I in, but unlike other iron squares, the figures are engraved to be read from inside the angle of the square.

    Source: R A Salaman, Dictionary of Woodworking Tools, c. 1700-1979, and Tools of Allied Trades rev ed, London: Allen and Unwin, 1975, page 475.

The Steel Square in the Woodshop

hexagon top on coffee table

with steel square, cutting hexagon top on coffee table

The Framing Square

The standard framing square has a blade, or body, 24 inches long and 2 inches wide, and a tongue 16 inches long and 11/2 inches wide. The blade forms a right angle with the tongue. The outer corner where the blade and tongue meet is called the heel. The face of the square is the side on which the name of the manufacturer is stamped.

A framing square made of stainless steel will not rust, an item of great importance when selecting any tool. Galvanized, copper- or nickel-plated squares are also rust resistant; however, the plating on these squares is apt to wear off in the course of time. A copper-plated square has the advantage of white figures, and the division marks can be read more easily than similar marks on the stainless-steel square.

In addition to the convenient division marks and the rust-resistant material, it is advisable to select a square which has useful tables stamped on it; for example, the rafter-framing table, Essex board measure, octagon scale, and brace measure. Rafter-framing tables vary with different makes of squares. Some are unit-length tables while others are total-length tables for the most common roof pitches. Although these tables are not always used, it is convenient to have them at hand when the need for them arises. After a workman thoroughly understands the rafter-framing tables, he uses them more frequently. A book of instruction usually accompanies each square and in this book the manufacturer has explained the various tables and how to use them. See also the chapter on the Framing Square in this text.

Framing Square-some of its Uses

steel_square_roofingTo a skilled craftsman in the trade, the square is almost as indispensable as the hammer, saw, or plane. To the inexperienced the square may be merely a tool for use in drawing lines at right angles, or for testing a board to determine whether or not it is straight and true. However, in the hands of a skilled workman who understands how to use the scales and tables on the framing square, it is a highly valuable tool and an essential part of his equipment. Therefore, it is advisable for the mechanic not only to acquaint himself with the fundamental operations performed with the square but also to become familiar with a few of the special layouts where the square is useful for solving common construction problems. The framing square serves woodworkers not only as an multi-faceted tool but also as a handbook and instructor. The use of scales and tables given on the framing square avoids complicated mathematical computations which would consume much of the carpenter's valuable time. Information regarding lines and angles presented by means of scales and tables on the square is simple, practical, and condensed. The laying out of the various cuts is illustrated in a step-by-step method which makes some of the most difficult operations seem easy. There are many different makes of framing squares and various finishes are applied to different makes. The scales and tables vary with the cost and make. When buying a framing square, it is advisable for a mechanic to spend enough money to secure one with complete tables and scales because they supply information particularly valuable on the job, making the square comparable to an engineer's handbook. The chief difference in the tables of the various kinds of framing squares is found in the rafter table, as some tables are based upon unit length and others upon total length. Since space will not permit description of all of the tables, the one most frequently used - the unit length table-is the only one explained in detail in this book. The locations of the various tables and different graduations, or scales, are shown in Fig. 50.

Testing a Framing Square

Smooth up one side of a wide four-foot board. Dress one edge of the board until it is a true straight edge. Then lay the prepared board on the workbench with the straight edge turned toward you and the smoothed face turned upward. Place the square on top of the board with the blade, or body, extending to the left and the tongue at right angles to the straight edge of the board. Hold the square firmly in position with the entire length of the blade aligning perfectly with the straight edge of the board. The tongue will then be extending away from you across the board, as shown at (1), Fig. 51. While still holding the square exactly in line with the edge of the board, take a penknife or a extending to the right along the straight edge of the board and exactly in line with this edge throughout the entire length of the blade of the square, as shown at (2), Fig. 51. Always hold the square firmly in place along the edge of the board and keep the heel exactly where it was before the square was turned over, then compare the position with the mark which you made across the board. If the edge of the tongue is exactly on the mark, or if a new mark made with the penknife or pencil against the edge of the tongue, in its new position, coincides exactly with the first mark drawn, then the square is truly square.

If the angle of the square is found to be less than 90 degrees it can be brought back to the correct position by careful hammering of the metal in the heel. The hammering of the metal stretches it at this point, throwing the end of the tongue outward.

Essex Board Measure

A series of figures known as the Essex Board Measure appears on the back of the blade of the framing square. These figures provide a means for the rapid calculation of board feet, the unit of measure for lumber. A piece of board one foot square and one inch thick contains one board foot. A piece of board 1 foot long, 1 inch thick, and only 6 inches wide contains 1/2 foot board measure. Another piece 2 feet long, 1 foot wide, and 1 inch thick contains 2 feet board measure (f.b.m.). We use the term feet board measure when referring to quantities of lumber and when determining buying or selling prices of lumber or timber.

You can find the feet board measure for any size of board or timber by arithmetic, but the process can be simplified greatly and much time saved by turning directly to the back of the blade of your framing square. When holding the blade in your right hand and the tongue in your left hand with the heel pointing outward, that is, away from your body, you will be looking at the back of the blade of the square. With the square held in this position, you can observe the inch divisions 1, 2, 3, 4, 5, and so on, along the outside edge of the square, Fig. 52. These figures show the width in inches of the stick of timber or board to be measured. Under each of these widths seven other figures appear. These figures give directly in feet (to the left of the vertical line) and in twelfths of a foot (to the right of the vertical line) the feet board measure, in boards of that particular width one inch thick, of seven different lengths. These lengths beginning at the top edge of the blade under the 12-inch mark and reading downward are: 8, 9, 10, 11, 13, 14, and 15 feet. The Essex board measure gives the numher of board feet of practically all the sizes of boards or timber in common use. To find feet board measure the inch graduations, along the outer edge of the back of the blade of the square, are used in combing tion with the values given along the seven parallel lines.

The figure 12 at the outer edge of the back of the square represents a board 12 inches wide and one inch thick, Fig 52. This is the starting point for all calculations. The numbers in the column directly under the 12-inch mark indicate the lengths of a piece of board in feet. The regular inch divisions of the square on each side of the 12-inch mark represent the widths of the boards in inches. The figures under each of these inch division marks represent the number of board feet and the twelfths of a board foot.

When you wish to find the feet board measure of a particular piece of lumber, first find under the 12-inch mark the figure corresponding to the length (in feet) of your stick of timber. Then follow along the horizontal line under this figure to the left until you come to the point under the inch mark corresponding to the width (in inches) of your stick, and there you will find the figure which gives the contents of your stick of timber in feet board measure. The figure appearing at the left-hand side of the vertical line is full feet board measure and Steel Rules ?

Sources: Peter Nicholson, The Mechanic's Companion, Or, The Elements and Practice of Carpentry ... - Page 42 1845 - Frederick Hodgson The Carpenter's Steel Square and Its Uses New York: Industrial Publication Co., 1883,

; Walt Durbahn, Fundamentals of Carpentry: Tools, Materials, Practice Chicago: American Technical Society, 1947, Volume 1; U. L. Hiatt The Steel Square: its Use Gunnison, CO: Western State College of Colorado, 1954; Aldren A Watson, Hand Tools: Their Ways and Workings New York: Lyons and Burford, 1982;