A speed square is handy for marking cuts, finding angles, and more. Here are a few good reasons why no toolbox should be without one.

You can use a Speed Square to build sheds, firewood racks, picnic tables, Adirondack chairs, benches, saw horses, even a boat. You name it, and a Speed Square will help you make it.

The Brass Goniometer, an ancient device used to measure angles and orient objects in space, is the foundational concept behind the Y Ruler.