What Is a Carpenters’ Square?
A carpenter’s square is a right-angled, folded shape, consisting of straight longitudinal and transverse measures, connected at precise right angles to each other. It is often made of metal and used to measure the length of one side of a piece of wood or steel. It is also used to draw an accurate straight or curved line using the deflection and steel properties of that metal.
Uses of the Carpenters’ Square
Because of its structure, carpenters’ squares are tools mainly used by carpenters, architects, and other craftsmen who work with building materials. Many timbers and steel materials are round, and they are used to measure rectangular square posts with a length of one side that can be easily obtained from the measurement of their cross sections, or for advanced measurement purposes in carpentry work.
In fact, the history of the Carpenters’ Square is ancient. It is said that carpenters’ squares have been widely used in China since the Han Dynasty and in Japan since the Heian Period (794-1185), and books related to carpentry were published in the Edo Period.
Principle of the Carpenters’ Square
The principle of the carpenters’ square is that the front side has a metric scale in millimeters, and the back side has a number obtained by multiplying the number on the front side by the square root (root) of 2 and dividing by the circumference of the circle. The former number is sometimes referred to as the square root and the latter number as the round root.
Most carpenters’ squares are made of metals such as brass (brass), stainless steel, and copper, and the above scales are usually found on both long and short right-angled measures.
As an example of how to use this system, if you apply the carpenters’ squares to the diameter of a log, you can see at a glance the length of one side of the square or the circumference of that log that you can obtain from it. However, it is not easy to determine the diameter of a log that is not a circle accurately.
Therefore, using the carpenters’ square to define the circumference angle, the right angle of the carpenters’ square is placed on the circumference of the log, and the long and short sides of the carpenters’ square is marked where it intersects the circumference of the log. Repeat this process to find the approximate center of the log, which is not exactly a circle.
Another advanced use of the carpenters’ square, other than for measuring right angles, is to determine the appropriate combined length of roof slopes and columns with non-right angles by cleverly using the relationship between the square root numbers of similar triangles.
Architects, carpenters, and other professionals should choose a product that guarantees high dimensional accuracy.