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Price Guarantee:
At Acme Tools we pride ourselves on offering you the best selection of tools, equipment and supplies in the industry at guaranteed low prices. From time to time we are not always able to see what the competition is doing. Our product is priced as low as possible. However, our prices won't be beat. If you see the exact item currently advertised for less (including the competitor's shipping and handling charges, taxes or any other hidden charges) we should be able to match that price. We reserve the right to verify current and net prices in these situations. See terms and conditions below. In the event of finding a lower price, use our Contact Us form and include the following information in the Comments Section for verification: Your order number, date of purchase, product number of item as well as the competitor's website and price. We will review the information, issue credit (if applicable), and get back to you within two business days.

Terms and Conditions:
  • The seller must be an authorized retail dealer.
  • Product must be in stock and an identical item.
  • This policy does not apply to auction sites, closeouts, clearance sales, misprints, giveaways, special promotions or discount offers and may not be used in conjunction with any other Acme Tools offers or coupons.
  • This policy is only valid within 30 days after your purchase date.
  • Your refund will be issued in the same form as your original payment.
  • Heavy Equipment does not qualify.
$20 .99
$20 .99


The Big 12® Speed® Square is a 12-inch version of the Swanson® Speed® Square with added features for building stairs. This innovative tool combines 7 tools into 1: 1. Try Square, 2. Miter Square, 3. Saw Guide, 4. Line Scriber, 5. Protractor, 6. Out-of-Square Corner Angle Finder, and 7. Stair Layout Square. The Big 12® Speed® Square is die-cast for durability and accuracy. Made of heavy-gauge aerospace aluminum alloy, it is built to last. Black-filled gradations stand out against a matte finish for easy reading and are simple to use with the Swanson® One-Number® Method of rafter layout. This model includes the Swanson® Blue Book for Roof and Stairway Layout as well as the Layout Bar™ for use in determining out-of-square corners when building stairways. The Swanson® Speed® Square is our most popular product and remains the most trusted square of its kind. Look for the Diamond® cutout for genuine Swanson® products.

WARNING: California's Proposition 65

  • 12-in. version of the Speed® Square, made in the USA since 1925, is essential for every carpenter, construction professional, roofer, and DIYer
  • Great for deck framing and stairway building!
  • Multi-tool: try square, miter square, saw guide, line scriber, protractor, out-of-square corner angle finder, and stair layout square. For what it does, the Speed® Square belongs on every tradesman's tool bench
  • Includes Swanson® Blue Book—a guide with our One-Number® Method to help make correct angle cuts for any pitched roof and bonus content for basic stairway layout
  • Features: 1/4 in. and 1/2 in. spaced scribing notches and the Diamond® cutout for easy rafter seat cuts and scribing the most common and popular stud widths
  • Gradations included for marking common, hip, valley, and jack rafters. Useful for determining and marking angles and making square cuts on boards
  • Heavy-gauge billet aluminum alloy construction is die-cast for increased accuracy over laser-etched and extruded stamped rafter squares
  • Includes patented Layout Bar™ for repeated cuts and determining out-of-square corners
  • High-visibility, black gradations with a non-glare, matte finish for easy reading in any lighting conditions
  • When used as a saw guide, the Speed® Square makes truing up a board easy
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