How to Use a Framing Square

A framing square or steel square is a tool used by carpenters. It is used for many different kinds of measurements but most notably it is used to measure angles and right angles. It is usually made of metals like aluminum, making it more durable and resistant to rust. It is comprised of a small arm and a long arm that are perpendicular to each other, creating a 90 degree angle. The wider of the two arms which is two inches wide, is referred to as the blade. The thinner arm is one and a half inches in width and as is deemed the tongue. It is extremely useful when laying out stairs, rafters and hip rafters. It utilizes a diagonal scale, octagonal scale and a board foot scale. The newer models also include degree conversions for various pitches and corresponding fractions. A framing square may be used in a variety of carpeting projects. It is relatively easy to use once you are able to replicate effective measuring techniques. Some amount of mathematical competence will be necessary for greater accuracy. However, with practice you will likely be able to use the framing square for more difficult projects.

Things You Will Need

  • Framing Square
  • Board


  1. The wider part of the faming square as mentioned before is the blade. It is used to measure the horizontal cuts.
  2. The tongue or the thinner area of the square will measure vertical cuts.
  3. Fist you will need to determine the dimensions of the project. This simple means you will be required to know the height and distance at inception. Place the framing square on the periphery of a 2 by 12. Mark the left hand side to indicate the rise and the right hand side to denote the run.
  4. You will then need to outline the L shape made in the board by using the edge of the framing square. Move upwards and create another L shape above the initial L shape. Continue the process of marking the L shape until you have covered the length of the 2 by 12 with these markings. This will yield the initial portion of your stair stringer. It may also be used to cut your roof rafters.
  5. Place the square diagonally over the board to create a roof pitch. On the areas where the square traverses the board on each end, use the number for the rise to run determined by the numbering on the square to trace the end of the square on its diagonal. This will produce the peak of the roof where it will be positioned on the wall.
  6. For greater accuracy you may use a calculator to acquire the precise measurements that will be used, more specifically for the pitch run, layout rafter and test. It is also possible to complete the measurements using the top edge of the framing square.

Do’s and Dont’s

  • Use the charts on the framing square when creating the frame for the rafters. This will aid in making the correct calculations.
  • Once you are finished using the square, use a circular saw to cut the rafter and use it as a pattern when cutting other rafters.

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