What is the diamond for on a speed square

Squaring Lines The Swanson Speed Square has a diamond cutout along the ruler that allows you to square lines and make sure they’re perfect. That diamond cutout can be used to make a notch, or a birdsmouth, for rafter work.

How do you find the angle between two walls?

Divide half the length of the measurement between the two walls, the opposite side, by the length of the wall between the intersection and either measuring point, the length of the hypotenuse. This calculation determines the Sine of the angle.

How do you find the angle in framing?

In carpentry, you usually do away with trigonometric functions to find angles. Instead, you simply use two legs of a triangle to measure and mark the angle. Call one leg the rise, designating the height of the triangle, and the other leg the run, or the length of the triangle.

What do all the numbers on a framing square mean?

How to Cut Stair Stringers with a Framing Square. Measure the rise (vertical distance) and run (horizontal distance) of the area your stairs will occupy. Divide those measurements by the number of stairs you want to have. This should produce two numbers—one for rise, one for run.

How do you lay out a 45 degree angle?

1. Construct a perpendicular line.
2. Place compass on intersection point.
3. Adjust compass width to reach start point.
4. Draw an arc that intersects perpendicular line.
5. Place ruler on start point and where arc intersects perpendicular line.
6. Draw 45 Degree Line.

What saw to use to cut birdsmouth?

First of all, you need a couple of saws. A circular saw and a hand saw work best for making birdsmouth rafter cuts. If you’re doing construction on your own home or on a shed for your property, you may already have one or both of these saws close at hand; but if not, you may want to consider purchasing them.

Is birdsmouth cut necessary?

A lot of force is transferred down the length of the rafter, and the seat cut on the birdsmouth transfers that force directly to the top plate. … In general, while the ripped-strip installation does eliminate the need to make two cuts for the birdsmouth, it’s debatable whether there are any real labor savings.

What is a sliding T bevel used for?

A sliding T bevel, also known as a bevel gauge or false square is an adjustable gauge for setting and transferring angles. Different from the square, which is fixed and can only set a 90° angle, the sliding T bevel can set any angle and transfer it on another piece.

How big should birdsmouth cut be?

In a properly-cut bird’s mouth, the length of the horizontal or level line (below my two red arrows in the page top photo) should be about equal in length to the width of the top plate.

What is the number 17 used for on a framing square?

Seventeen inches is used because that’s the unit length of any diagonal on a square whose sides are 12 inches (see top left corner, “Exercise 2”). As the process of stepping-off a hip is done, the carpenter is reinforcing the diagonal-to-square relationship, and this paves the way for other layout know-how.

Article first time published on

What angle do you cut wood to make a square?

The term “square cut” means to cut a board at a 90 degree angle relative to one of it’s edges.

What are scribe notches?

Scribe-Guide™ precision scribe notches allow for fast, accurate marking on the jobsite. + High-visibility laser etched markings allow for accurate, easy-to-read measurements every time. + A 15% wider heel allows the square to maintain a secure hold on lumber and other jobsite materials.

What is a hip Val on a speed square?

Hip/Val indicates the rise in inches over a 17 inch run for hip or valley rafters from 1 inch to 30 inch.

How do you know if a construction angle is right?

1. Measure 3 feet out from the angle you want to make 90° in one direction.
2. Measure 4 feet out from the angle you want to make 90° in the other direction.
3. Measure across the two points and adjust the angle until the distance on the third side of the triangle is 5 feet.

What is the length and width of the shorter side of the framing square?

The longer, two-inch-wide portion of the square is the blade. The shorter leg is called the tongue, and it is one and a half inches in width. The outside corner where the blade and tongue join is the heel. The flat surface that has dimensions stamped on it is the face; its reverse side is known as the back.

Which square is engraved or printed with tables?

A carpenter’s square, also called a framing square, is a versatile instrument for laying out stair stringers, roof rafters and determining angles, among other duties. Usually made from aluminum or steel, carpenter’s squares are etched with tables and numbers that go beyond a simple ruler.