What is the Best Combination Square For Woodworking? (2024)

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A combination square can be a very helpful tool for woodworkers because it’s versatile enough to provide any necessary measurements. 

But trust me, picking the wrong one can ruin your projects and even hurt your hands. To help you choose a precise and safe model, I’ll share some of the best combination squares I rely on for different tasks in my workshop.

Premium Option
WorkPro Rafter & Combo
Editor’s Choice
Starrett C11H-12-4R
Budget Option
Irwin Tools 1794469
WorkPro Rafter & Combo
Starrett C11H-12-4R
Irwin Tools 1794469
• 12-inch blade length
• Spring screw
• Rafter included
• 3 types of scale
• Built to last
• Accurate
• 4R graduations
• Versatile
• Rustproof blade
• Cast zinc material
• With speed square
• Black etched labels
Premium Option
WorkPro Rafter & Combo
WorkPro Rafter & Combo
• 12-inch blade length
• Spring screw
• Rafter included
• 3 types of scale
Editor’s Choice
Starrett C11H-12-4R
Starrett C11H-12-4R
• Built to last
• Accurate
• 4R graduations
• Versatile
Budget Option
Irwin Tools 1794469
Irwin Tools 1794469
• Rustproof blade
• Cast zinc material
• With speed square
• Black etched labels

Reviews of the Top Combination Squares

1. Starrett Steel Combination Square (C11H-12-4R)

This Starrett C11H-12-4R combination square is renowned for its pinpoint accuracy in terms of its general structure and the precision of the blade’s number markings.

The wrinkled texture on the head of this hammer, constructed of durable cast iron, makes it easy to keep a firm grasp on the tool while you work. The spirit level is a handy addition, and the glossy chrome finish on the blade makes it simple to read.

The square features all the things you need to measure length or miter, scribe right angles, level tri-squaring and parallel lines, as well as gauge height and depth.

What I Like

What I Don't Like

2. WORKPRO Rafter Square and Combination Square Tool Set

When I first laid eyes on the WORKPRO Rafter and Combination Square Set, it gave off an impression of sturdiness. I was pleasantly surprised by the added carpenter square, a bonus I genuinely appreciated.

The level vial and metal scriber are incorporated right into the ruler, and the spring-loaded screw makes it easy to remove the ruler. Furthermore, the integrated level and the removable brass scriber add to its convenience.

The ruler is sturdy, and its fractional marks are easy to read. However, they can be hard to see without distinguishing markers at reasonable intervals like 1/2 inch and 1/4 inch.

What I Like

What I Don't Like

3. Irwin Tools 12-inch Combination Square, 1794469

I’ve always had a soft spot for Irwin Tools, mainly because they masterfully balance cost with quality. Take this square, for instance: its rust-proof stainless steel blade coupled with a cast zinc body is a testament to its durability and resistance to corrosion.

In addition, the 90 and 45-degree markings are etched deeply into the ruler’s surface and painted black for legibility. There are a variety of imperial and metric measures on one side of the blade, making it the most flexible combination of squares available. 

The built-in bubble level and scribing tool simplify the leveling process, making tasks quicker. Given its 12-inch length, I’ve found the Irwin 1794469 Combination Square especially handy for several home improvement endeavors, kitchen cabinet remodeling being a prime example.

What I Like

What I Don't Like

4. Swanson Tool Co TC130 6-Inch Combo Square

This small combination square is easy to read because the markings are carved in black. The 6-inch length of its blade is marked in both metric and imperial units. 

Furthermore, the use of stainless steel in its construction guarantees the precision and durability of this tool. Die-cast zinc, used in constructing these combination square sets, is very resistant to rust and contributes significantly to the set’s overall robustness.

The Swanson Tool Co TC-130 has a heavy-duty bubble level and a built-in brass scriber for quick marking. The blade is held in position by a spring-loaded bolt, ensuring that your angles will not change and ruin your aim.

What I Like

What I Don't Like

5. Johnson Level & Tool 400EM-S

The cast-zinc head of the Johnson 400EM-S Combination Square is extremely durable, and the chip-resistant coating ensures it will withstand even the toughest treatment in the workshop. 

The screw-in scriber adds to the product’s durability, and the blade’s auto-lock mechanism makes it easier to position instruments before use. Its blade is made of stainless steel and features an imperial and metric scale. 

This metal square ruler has been treated by a computer numerically controlled machine, making it excellent for marking as a straight edge, miter square, adjustable try square, and depth gauge, among others.

What I Like

What I Don't Like

6. Mr. Pen- Combination Square, 12" Combo Square

The Mr. Pen 12-Inch Combination Square measures 12 inches in length and has a die-cast zinc head to prevent rusting. The blade is marked clearly and is made of stainless steel.

This combination ruler features a centimeter scale with 1 millimeter (1/10 of a centimeter) divisions and an inch scale with divisions down to 1/32 of an inch. The package also has a scriber and a bubble level.

While the blade and the head casting aren’t the thickest in the market, this tool provides remarkable value for its price point. Plus, given its affordable cost, obtaining a replacement won’t burn a hole in your pocket.

What I Like

What I Don't Like

7. iGaging Premium 4-Piece 12" 4R Combination Square

This all-inclusive set is exactly what I turn to when I need to inspect, measure, or handle a range of angle measurements. While a typical combination square might be limited to one dimension, this particular one impresses has a protractor, center, and square heads, extending its utility for multiple tasks.

The 24-inch length of the blade and the square design of the head make this instrument suitable for even the most extensive of measurement tasks. This kit’s components can be safely kept together in a sturdy carrying case while they’re not in use.

For those in search of a top-notch instrument that doesn’t strain the wallet, I’d personally recommend the iGaging Premium 4-Piece Combination Square, even if it might not be as renowned as other brands.

What I Like

What I Don't Like

How Do Combination Squares Work?

Combination squares are multipurpose marking and measurement tools that see widespread application in the construction industry. 

They come with a precise ruler and a selection of interchangeable heads to meet the requirements of every task. These squares come in various names, including adjustable and sliding.

3 Types of Combination Squares

Protractor Head

Angles between lines, corners, and flat surfaces can be measured and analyzed with the help of protractor heads. You may adjust the angle of your blade to any value between zero and 180 degrees by attaching a protractor head to it.

Protractor heads with a center head allow you to precisely mark angles off a reference point. Like a bevel gauge, this head can directly transfer angles with minimal margin for error.

Center Head

The centering head is useful for locating the geometric center of square and round objects, such as dowels. If you want to pinpoint the exact center of an object, marking many points at varying degrees of rotation can help. 

Additionally, you can use it with perpendicular angles on a curved surface. A locking thumb nut is located close to the edge’s tip, and the body is formed like a “V.” One major benefit of this design is that the blade can easily slide into the center of a head.

Squarehead

This is the industry standard head for garages and job sites. It can be used as a miter square or a try square due to its 90-degree and 45-degree edges. Miter squares serve to mark and reference 45-degree angles, while square heads are utilized to designate 90-degree angles.

A square head includes height and depth indicators making them a multi-purpose handy tool.

Why is it Necessary To Use a Combination Square?

The best combination squares are one of the most useful and inexpensive items you can add to your workshop.

Assessing for square, striking 90- and 45-degree lines, scribing rip cut and joinery lines, gauging material thickness, aligning saw blades, and calibrating tool heights to 90-degree angles are some of their most popular uses.

How To Check if Your Combination Square is Indeed Square

Use a sheet of wood with a planed edge, like plywood or MDF, to verify the square’s precision. You can check if your board is square by holding a ruler up to it with the head at one end.

Just take a pointed pencil and scribble a line down the length of the knife. You can make a mirror image of the head by flipping the combo square over. Make a second line across the blade, with the base resting at the end of the first.

Both lines must be parallel to one another. If the two lines create a shallow “V,” the square is off and needs to be calibrated.

How To Fix Your Square

An uneven groove to rest the ruler is a common cause of problems. Because of this, the ruler’s angle isn’t quite 90 degrees but is slightly off to one side.

A bit of sandpaper will fix this. Identifying the taller of the two sides is required. The unevenness is sanded away with a little touch on the head’s side. After sanding, use the same method to ensure perfect squareness.

Combination Squares Buyer’s Guide

Accuracy and Size

The “blade” of a combination square indicates the total size. The smallest models feature 4-inch blades, the longest 24-inch.

A 4-inch combination square can be folded and stowed in a toolbox, but a longer blade is better for laying out or inspecting the square. While 12 inches is the most versatile size for a combination square, there are also larger sizes available.

Material and construction affect a tool’s precision. Consider slashes, too. “4R” scale has 1/8-, 1/16-, 1/32-, and 1/64-inch marks. Cheaper models’ accuracy may degrade. Models have metric, inch, and hybrid measurements.

Blades have several patterns. Cheap tools have blades punched from metal sheets, and the same punch makes divisions causing blurred lines. While scale markings might fade, higher-quality combinations have machine-etched marks, allowing for better precision.

Readability and Markings

Combination square markings are crucial to their endurance. Painted markings are originally apparent but fade with use. Measurements could become ambiguous if the same machine carved the square’s markings as its blade.

Etched blade markings don’t disappear easily. These markers provide precise, unambiguous, and reproducible readings.

Build Material

Combo squares have stainless or hardened steel blades; stainless steel is rust-resistant but weaker than hardened steel, while hardened steel is less rust-resistant.

Stainless steel is popular because it resists rust and is durable; if you like harder steel, make sure it’s chrome-plated.

Cast iron, polystyrene, and zinc are used to make combination squares. Plastic tools are cheap but degrade over time. Die-cast zinc is popular for reducing rust and preserving precision. Cast iron combo squares are durable but must be cleansed after every use.

Versatility and Application

The replaceable heads of combination squares make them useful in various woodworking applications. Depending on the project’s needs, you can swap out the protractor head for a center head or vice versa.

Invest in a high-quality assortment of combination squares if you’re working on a project requiring all of these different angles of approach. Moreover, a center finder head, scriber, and spirit level are included in some models, making them even more useful and accurate. [1]

Size of the Blade

Combination squares typically come in one overall shape, but they are available in various sizes. The most common sizes you’ll find are four-inch, six-inch, twelve-inch, sixteen-inch, and twenty-four-inch.

In an emergency, having many sizes on hand is ideal, but if you must choose just one, a 12-inch combination square can provide the most flexibility.

FAQ

How do I properly use a combination square?

The combination square’s adaptability is one of its greatest strengths. Use the ruler to measure distances and the base of the handle to measure height and depth. The bubble, if present, serves as a leveler, while you can use the square section to designate 45- and 90-degree angles.

How precise are combination squares?

The age and condition of the model are major factors in its accuracy. Although most are made to within 0.001 inches of tolerance, friction can nevertheless cause guideways and screw threads to loosen with time. In contrast to low-cost models, high-quality tools will serve you for years.

How do I calibrate my combination square?

Take the knife out and loosen it. Make sure the groove the blade slides in is free of any debris since even a dust particle can throw it off alignment. Put it back together and double-check it as you did before using the steps in the previous solution.

How do I maintain my square?

The most common problem with any device is grime. When deposits build up, disassemble the device and clean the parts with a non-abrasive scourer and some spirit or rubbing alcohol. After the glue has dried, lubricate the blade slide with a small coating of paste wax.

My Top Pick for a Combination Square: Starrett Steel C11H-12-4R

My pick for the best combination square has to be the Starrett Steel C11H-12-4R. In my hands, it’s proven to be among the most versatile tools for obtaining accurate measurements.

The cast iron square head and the reversible lock bolt give me confidence in its longevity. Even though it comes at a premium price, it possesses all the essential features I’d expect from a top-tier woodworking square.

robert headshot

Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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