# Speed square > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Speed_square > Markdown URL: https://mediated.wiki/source/Speed_square.md > Source: https://en.wikipedia.org/wiki/Speed_square > Source revision: 1356552655 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{short description|Triangular tool used by carpenters}} {{More citations needed|date=May 2021}}thumb|A Swanson Speed Square A '''speed square''', also called a '''rafter square''', '''rafter angle square''', and '''triangle square,''' is a multi-purpose [triangular](/source/Triangle) carpenters' tool used for [marking out](/source/marking_out). Its functions encompass many of those offered by [combination squares](/source/combination_square), [try squares](/source/try_square), and [framing squares](/source/Steel_square). Carpenters use it to make basic measurements and mark lines on [dimensional lumber](/source/dimensional_lumber), and as a saw guide for short 45 and 90 degree cuts. "Speed Square" is a registered trademark of the Swanson Tool Company in the United States.{{Cite web|date=May 19, 2017|title=Trademark Status & Document Retrieval|url=https://tsdr.uspto.gov/#caseNumber=77222688&caseType=SERIAL_NO&searchType=statusSearch|access-date=2021-05-01|website=United States Patent and Trademark Office|quote=Mark: SPEED SQUARE [...] Goods and Services [...] For: Hand tools, namely, squares [...] Owner name: Swanson Tool Company, Inc.}}{{Cite web|date=May 19, 2017|title=Trademark Status & Document Retrieval|url=https://tsdr.uspto.gov/#caseNumber=73749206&caseType=SERIAL_NO&searchType=statusSearch|access-date=2021-05-01|website=United States Patent and Trademark Office|quote=Mark: SPEED [...] Goods and Services [...] For: HAND TOOLS, NAMELY; SQUARES [...] Owner name: SWANSON TOOL CO., INC.}} ==History== Albert J. Swanson invented the "A" Speed Square in 1925 as a carpenter's layout tool. He later founded the Swanson Tool Company to mass produce his invention.{{Cite web|date=n.d.|title=History|url=https://www.swansontoolco.com/company/history/|access-date=2021-05-01|website=Swanson Tool Company|language=en-US}} Today, the Swanson Tool Company still manufactures and distributes the Speed Square and other carpentry tools from its headquarters in [Frankfort, Illinois](/source/Frankfort%2C_Illinois). ==Design== The Speed Square is manufactured from a variety of materials such as [aluminum](/source/aluminum), [steel](/source/steel), and composites such as [HDPE](/source/HDPE). They are also made in several sizes such as {{cvt|4|,|6|,|7|,|8|and|12|in|mm}}, and 250 mm. Embedded degree gradations on the tool eliminate the need for [trigonometric](/source/trigonometry) calculations and allow for lines to be more easily made. The Speed Square tool is an [isosceles](/source/Isosceles_triangle) [right triangle](/source/right_triangle) with a ruler on one equal side and a [fence](/source/Fence_(woodworking)) on the other. It is marked with the word ''Pivot'' at the right angle point and displays ''Degrees'' on its [hypotenuse](/source/hypotenuse), ''Common'' and ''Hip/Val'' markings on its midsection. *''Degree'' indicates the angle in degrees from 0° to 90°. *''Common'' indicates the rise in inches over a 12 inch run for [common rafter](/source/rafter)s from 1 inch to 30 inch. *''Hip/Val'' indicates the rise in inches over a 17 inch run for hip or valley rafters from 1 inch to 30 inch. Some models have divots for fitting a writing utensil to mark lumber with. Speed squares made by the Swanson Tool Company also have a diamond shape cutout on the ruler side at 3½ inches. ==Uses== Among its basic uses are marking common, [hip](/source/Hip_roof), [valley and hip](/source/Rafter), or [valley jack rafters](/source/Rafter), laying out stair [stringers](/source/Stringer_(stairs)), determining and marking angles, and making square cuts on boards. Common lines made using a speed square include perpendicular cut marks and Angles [https://www.thoughtco.com/definition-of-an-angle-2312348 definition of an angle] for roofs, stairways, and decks. The tool uses a 0° reference. This means when a board is squared off the tool reads 0°. The angle derived is actually a [complementary angle](/source/complementary_angle), for example a 22.5° angle is actually 67.5°. The sum of the angles equals 90 degrees (22.5° +67.5°= 90°). It is also obvious from a visual check when using a [protractor](/source/protractor) that where the instruments displays 22.5° is actually 67.5° on the protractor. Many newer slide [miters](/source/Miter_saw) and [miter boxes](/source/Mitre_box) display both angles. Some of the new calculators have a 0° and a 90° references. The only true angle is 45° on the triangular square. This can create confusion if the user does not understand this angular calibration when using trigonometric functions. The FIRST image below shows ''' ⊾''' P = 20° on the protractor and '''⊾ '''T = 20° on the angle Square. The only similarity is that both of the angles are [acute angle](/source/acute_angle) and complimentary. When the image is enlarged the protractor is on the '''⊾''' 20° index and the body rests on the edged face of the 2X4. The square is pivoted on the (left side 2x4) and locked into the '''⊾''' 20° degree index at the red marked line. The SECOND image displays '''⊾''' X = 70° on the clear protractor that is graduated in 360°, '''⊾''' X = 20° on the Aluminum angle square. Both red lines '''⊾''' X are Parallel and thereby congruent. "Postulate 4.1 (P 64)" congruent angle *{{ISBN|978-0-7641-3918-5}} File:Aluminum Angle Square and Plastic Protractor 02.jpg|Differences of angle square and protractor File:Clear Protractor 01.jpg|20° on protractor and angle square ==See also== * [Combination square](/source/Combination_square) * [Steel square](/source/Steel_square) * [Try square](/source/Try_square) ==References== {{Reflist}} ==Further reading== * {{cite book |title=The Steel Square |last=Siegele |first=H.H. |publisher=Sterling Publishing |year=1981 |isbn= 0-8069-8854-1}} * {{cite book |title=Barron's E-Z GEOMETRY |last=Leff |first=Lawrence S |publisher=Baron's Educational Series |year=2009 |isbn=978-0-7641-3918-5}} == External links == *[http://zo-d.com/stuff/how-do-i/how-to-use-the-swanson-speed-square-as-a-framing-square.html How to Use a Swanson Speed Square as a Framers Square] *[http://www.homeconstructionimprovement.com/2008/08/how-to-use-swanson-speed-squares.html How To Use A Swanson Speed Square] *[https://www.youtube.com/watch?v=_Rraefmk7F8 SPEED SQUARE MADE SIMPLE] (video) ===News=== *[https://www.woodcraft.com/blog_entries/playing-the-angles.html Playing The Angles. Is it 90°or is it 0°?] *[https://www.popularmechanics.com/home/tools/a41134984.html how to use a speed square] *[https://www.finehomebuilding.com/?s=Speed+Square+Hacks.html Speed Square Hacks] *[https://books.google.com/books?id=oNTAFoj1FQsC&dq=%22Speed+square%22+-wikipedia&pg=PA45 Framing Basics] *[https://www.math.net/complementary Complementary Angle] *[https://www.thoughtco.com/definition-of-an-angle-2312348 Definition of an angle] ===Books=== *[https://books.google.com/books?id=tjneDwAAQBAJ&dq=%22Speed+square%22+-wikipedia&pg=PA79.html Girls Garage] *[https://books.google.com/books?id=oNTAFoj1FQsC&dq=%22Speed+square%22+-wikipedia&pg=PA45.html Framing Basics] {{Measuring and alignment tools}} {{Authority control}} {{DEFAULTSORT:Speed Square}} Category:Woodworking measuring instruments Category:Dimensional instruments Category:American inventions Category:Squares (tool) --- Adapted from the Wikipedia article [Speed square](https://en.wikipedia.org/wiki/Speed_square) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Speed_square?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.