Swanson Aluminum Speed Square Review

Swanson Aluminum Speed Square Review

The Swanson Aluminum Speed Square is one of our top 10 go-to tools in the framing and construction business. It is simply one of the tools you will invariably keep in your tool belt. You’ll find yourself using it for cutting simple lumber. You can also make complex angle calculations and measurements on roofing trusses. We decided to take a look at a few of Swanson’s classic Speed Squares and highlight some of the improvements they’ve made on the latest models. Today, we’re looking at the Speed Square Pro (S0100-A), Speed Trim Square (S0145), 7-inch original Speed Square (S0101), and the Big 12 Speed Square (S0107).

Swanson Aluminum Speed Square Foundations

Back in 1925, Albert J. Swanson had an idea to determine the pitch of a roof and the Swanson Speed Square was born. By 1930, there was enough demand for his innovative product to begin commercial interstate sales.

To this day all other rafter squares essentially model their products after his design. Many years ago I was using a standard combination square to measure and cut a piece of lumber when a contractor friend of mine sauntered over and handed me his Swanson Speed Square.

Like Swanson, I’ve never looked back. Swanson aluminum Speed Squares are a refreshing new take on the original steel models, offering the same accuracy with a lighter design than the original die cast models.

Swanson Aluminum Speed Square: The New Generation

The Speed Square Pro and Speed Trim Square start with all the features of the original Swanson aluminum Speed Square we’ve been using for more than a decade. They take it up a notch to include some really helpful measuring tools. These improvements make on-the-fly measurements and layouts faster and easier than ever before.

Swanson Speed Square Pro S0100-A

Swanson Aluminum Speed Square:

The S0100-A maintains the same dimensions and general feel as the original but adds a few new tricks.

What’s New?

  • Large bold indicator markings
  • 2x longer scribe bar than the original speed square with notches every 1/8-inch
  • 1 1/2-inch edge to help mark both sides of a 2x stud
  • 22 1/2° angle indicator coming off of the pivot lets you make quick and accurate layouts when framing
  • Diamond indicator at 5-1/2 inches for quick measurement when working with 2×6 material
  • Beveled edges get the square’s markings closer to your working material so you can make more accurate top cut measurements
  • Price: $13.98

Swanson Speed Trim Square S0145

Swanson Aluminum Speed Square:

The Trim Square is a pint-sized version of the original, measuring just 4 1/2 inches. Don’t let its size fool you though. This capable square will help you greatly cut down on any guesswork the next time you’re working with shorter materials such as case and base.

What’s New?

  • Large bold indicator markings
  • Roughly half the size of the original speed square
  • 2 5/8-inch scribe bar with notches every 1/8-inch
  • Easily identify common angles with the bold markings 22-1/2°, 30°, 45°, and 67-1/2°
  • 3/8-inch drill guide hole helps you perfectly center drill bits on 3/4-inch stock
  • Dual reference base lets you accurately center mortise and tenon joints at 1/4-inch and 3/8-inch increments
  • Price: $12.99

Swanson Aluminum Speed Square: Tried and True Classics

Original Swanson Aluminum Speed Square S0101

The Swanson aluminum Speed Square measures 7 inches in length along its height and width. The tool is approximately 3/4 inches wide with two lips that can rest, on either side, against a piece of lumber for measurement. This tool is perfect for use as a square, miter square, protractor, line scribe (1 inch to 2 1/4 inches) or even a small circular saw guide. Lightweight at less than 8 ounces, it fits easily into most tool pouches.

  • Price: $9.98

Swanson Big 12 Speed Square S0107

The Swanson Big 12 Speed Square is a larger, more capable version of the standard Speed Square. It functions as the perfect tool for laying out stairways. I loved using this tool for laying out countertops that butt against non-square walls. Where I lived, many houses built in the 20s feature out-of-plumb and out-of-square walls, so I got a lot of use out of it.

This tool also includes a separate Layout Bar. It’s helpful when marking and adjusting for out-of-square corners.

The Big 12 Speed Square weighs more than its little brothers—about three and a half times more. It weighs 1 pound, 11 ounces with the Layout Bar attached. As such, this is an excellent tool to have in your arsenal, and while you may actually reach for it quite a bit while on the ground, it’s tough to carry in a tool pouch.

  • Price: $20.97

Swanson Aluminum Speed Square Build Quality And Design

All four models are made from a heavy gauge aluminum alloy and look exceptionally well-built. They feel as if they could withstand several drops from a multi-story building onto solid concrete. They feature deeply impressed markings for length, hip/valley measurements, scribe detents, and protractor degrees. That said, the Pro and Trim square’s markings are noticeably deeper and larger compared to the original’s markings.

Swanson aluminum Speed Squares

Swanson includes a diamond mark with these squares. Laid out properly with the plumb line of a rafter, this mark gives you a quick way to mark seat or heel cuts. Align the Diamond cutout at 3 1/2 inches square with the plumb mark, set the pivot point of the square against the rafter, and set the protractor (hypotenuse) side at the 45° mark. Scribe your line across the top from Diamond to pivot and you’re all set. If this all sounds like Greek to you, that’s no problem. Swanson includes its handy “Blue Book” for Rafter Lengths and Roof Construction.

Swanson aluminum Speed Square


The Swanson Speed Square is one of those staples of construction tools that no serious builder or journeyman should be without. If these heavy-duty aluminum squares aren’t your cup of tea, check out Swanson’s other offerings which are available in a composite plastic form at a fraction of the weight. Some even integrate a block level, so you can use them in additional ways.

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