Speed square

Carpenters use it to make basic measurements and mark lines on dimensional lumber, and as a saw guide for short 45 and 90 degree cuts.

The Speed Square is manufactured from a variety of materials such as aluminum, steel, and composites such as HDPE.

Embedded degree gradations on the tool eliminate the need for trigonometric calculations and allow for lines to be more easily made.

The Speed Square tool is an isosceles right triangle with a ruler on one equal side and a fence on the other.

Speed squares made by the Swanson Tool Company also have a diamond shape cutout on the ruler side at 3½ inches.

The square is pivoted on the (left side 2x4) and locked into the ⊾ 20° degree index at the red marked line.