clock menu more-arrow no yes mobile

How to Use and Carry a Speed Square

A speed square is a small but versatile tool, here are the many ways you can use it.

Ask This Old House general contractor Tom Silva demonstrates the amazing versatility of the humble rafter square.

A speed square, also called a rafter square or layout square, has a 90-degree marking edge and a 45-degree marking edge. In this video, Tom Silva demonstrates how to use a speed square, ways to use it, and how to create your own speed square holder.

6 Speed Square Uses

A speed square costs about $10 to $20 to buy. It’s really versatile and can be used as:

  1. Straightedge guide when crosscutting with a circular saw.
  2. A pivot point allows the square to be used as a protractor for marking angled lines.
  3. The square is ideally suited for laying stud locations for walls.
  4. Built into the square are several scribing notches, which provide a fast, easy way to mark layout lines or cutlines onto lumber.
  5. The perfect 90-degree corner of the Speed Square can be used to determine whether two boards form a precise right angle.
  6. You can also use a speed square to find the center of a circle by creating two diameter lines that run through the center of the circle—where they cross is the center.

How to Make Your Own Speed Square Holder

To keep the square close at hand, hang it on your tool belt with a hook or get a specially designed Speed Square pouch. You can also custom-make your own Speed Square holder from a PVC baluster.

4 Steps to Create Your Own Baluster

  1. Cut the baluster to length on a miter saw, then cut a stopped slot along one side with a table saw or router.
  2. Cut a ¾-inch-thick plywood strip to fit inside the PVC holder, and secure it with short screws.
  3. Attach a metal belt clip to the opposite side of the holder.
  4. Clip the holder onto your tool belt, then slide the Speed Square into the slot.

Tools Referenced in the Video