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Flexible Center Rules are great for layout when working from center lines and for laying out detailed joinery.

Chappell Universal Center Rules are made from .029” stainless steel and are flexible enough to work on round logs and uneven surfaces. The front sides have decimal inch rulings divided in the 1/4, 1/2 and 3/4 inch, with minor divisions in 1/20ths, as in all Chappell Universal products. The rulings top and bottom start from opposite zero points, allowing the rule to be worked from either side without flipping it over and reading upside down.

Model CR118 has a Fraction to Decimal Conversion Chart and Trigonometric Ratio Equations etched on the front side. The backside is a center rule with edge rulings to allow both center work and zero point work on the same rule.



Introducing the Chappell Universal Square

The Best Square in the Universe

The Chappell Universal Square is designed to meet the needs of the modern builder. The comprehensive rafter tables include virtually every possible rotational angle and length ratio for equal pitched, unequal pitched, hexagon and octagon roof systems, all in an easy to use, truly cross-platform format.
The rugged stainless steel construction and deep etched rulings ensures long life and will not rust.
The patented Universal Square will make you a better craftsman & builder and will last for generations. No batteries required. Made in the USA.

The Master Framer model #1824 and the Traveler model #1218 each have the unique patented Chappell Universal Square Rafter Tables. The front side body has a comprehensive Equal Pitched Rafter Table for determining layout of hip and valley roof systems with common pitches ranging from 2/12 to 18/12. The front side tongues have Unequal Pitch Rafter Tables for unequal roof systems ranging from 4/12 to 15/12 with a main common pitch of 12/12. The back side bodies have comprehensive Polygon Rafter Tables for 6 and 8 Sided Polygons. The backside tongues have Unequal Pitch Rafter Tables for roof systems with a main roof of 9/12. Made of 13 gauge stainless steel with deep etched rulings and tables, this square will last a lifetime. The Master Framer, model #1824 has a body 2" x24" and a tongue of 1-1/2" x 18". The Traveler, model #1218 has a body 2" x 18" and a tongue of 1-1/2" x 12".

Copyright 2020, Chappell Universal Square & Rule Co. LLC. All rights reserved.

Patented Features Include

• Expanded Equal Pitch
Hip & Valley Rafter Tables to Include 14 Key Rotational Angles and Length Ratios

• Unequal Pitch Hip & Valley Rafter Tables

• 6 & 8 Sided Polygon Rafter Tables

• Universal Cross Platform Tables allow Calculations in Metric or Imperial Units
—Inches or Centimeters—
Requiring No Conversions

• Solid 13 gauge Stainless Steel Construction
Precision, Durability & Will Never Rust

• Guaranteed to be Square
within .003 Inch

• 18" Tongue Provides Greater Layout Flexibility & makes a 3, 4, 5
Right Triangle—18, 24, 30

• Cut Complex Roof Systems like a Pro
with only a pencil & the
Chappell Universal Square.
Leave the Calculator at Home.

• 48 page Instruction Booklet Included

• Made in the USA
Rebuilding America square by square!


As with the Master Framer and the Traveler models, the inch scales on the Chappell Universal Center Squares are divided by the 1/4, 1/2 and 3/4 inch, and further into .05 inches. Combining the fraction and decimal units seamlessly—there is no need to convert back and forth from fractional to decimal units as the decimal or fractional units can be applied directly to the Decimal Inch Scale. The wonderful ease of this will become evident after only 5 or 10 minutes of working with any of the Chappell Universal Squares and you will wonder why it took so long for anyone to come up with this system.

The Model #912 Center Square has a body 1-1/2" x 12" and a tongue 1" x 9". Both body and tongue front and back have zero point decimal inch rulings on the edges and a center rule scale along the center of each leg. All scales in the decimal inch, with minor divisions at the 1/4 inch and further into .05 inches.

The Chappell Universal Models #69 and #34 Center Squares offer additional flexibility to marking and layout. Identical in all ways other than the size, the model #69 Center Square has a body 1-1/2" x 9" and a tongue 1" x 6". The model #34 Gauging Square has a body 1" x 4" and a tongue 1" x 3". The #34 is ideal for intricate layout and also for setting both circular saws and table saw blades to a perfect 90 degrees.

No matter what the marking or layout situation—from large scale compound roof systems, to the most minute and intricate furniture and cabinetry layout—there is a Chappell Universal Square that is right for you.

For the first time ever, you can now easily lay out and cut unequal pitched roof systems with the revolutionary Unequal Pitched Rafter Table on the Chappell Universal Square. Complex roof framing has never been so easy.


Chappell Universal
Center Squares

Center rules work great for detail layout when working from center lines. Chappell Universal Square & Rule is the first to combine a center rule with a square with the introduction of the models #912 & #69 stainless steel Center Squares.

Made from the same rugged 13 gauge 304 stainless steel as the Master Framer and the Traveler, the Chappell Universal Center Suares will add a greater flexibility in your layout whether it be laying out mortises in large timbers or the most intricate details in furniture and cabinetry. The Center Squares are guaranteed to be square within .003 inch. The solid stainless steel construction provides durability, precision and it will not rust.


Center Square #912

Center Square #69

Gauging Square

Rebuilding America
One square at a time!

Made in USA


Flexible Stainless Steel Center Rules


Model CR112 - 1"x12" Center Rule •

Model CR118 - 1-1/2"x18" Center Rule •

Flexible Center Rules are made from .029” stainless steel
Model CR112: 1” x 12” Stainless steel center rule
Model CR118: 1-1/2” x 18” Stainless steel center rule


To purchase Chappell Square products click here to go to the
Fox Maple Store


Now find all cut angle and length ratios to design and build Hexagonal, Octagonal and any Hip and Valley roof system with ease.

Superb Quality

To Last a Lifetime

Center Squares

Quality Guaranteed