Buying Guide: Combination Squares
Seeing all the options above, you can imagine the abundance of options available. However, there are some standard features you should look out for that can help you land on the exact right product for your particular needs.
Check out this detailed buying guide, helping you draw a clear picture of an ideal combination square in your mind, ensuring confidence in your purchase.
What Are Combination Squares?
Combination squares are versatile measuring and marking instruments used widely in woodworking, metalworking, and stone masonry. They include a detailed ruler and multiple interchangeable heads depending on the needs of a project. These are also known as sliding squares, combo squares, and adjustable squares.
The most common uses of these tools are:
- Distance measurements
- Finding depth
- Determining level accuracy
- Measuring the central points of circular objects
- Marking and testing 90-degree and 45-degree angles
Types of Combination Squares
Before considering essential features, understanding the types of combination squares can help with using them in a more versatile manner. Here are the basic types of combination squares you can use on different projects.
Squarehead
A “square head” is a standard type of combination square commonly used in workshops and construction sites. It has both 90 degrees and 45-degree edges, providing dual functions as both a miter square and a try square. Square heads are used for marking 90-degree angles, and miter squares are used for marking and referencing 45-degree angles.
Square heads are versatile and can also be used as depth and height gauges. Also, being on a spirit level allows it to check the level of surfaces.
Center head
The center, or centering, head allows you to find the center of the square and round objects like dowels. Marking multiple spots at different angles can help you with precisely determining the center point of objects. You can also use it with perpendicular angles on a curved edge. The edge has been molded in a v-shaped body, and a locking thumb nut is present near the endpoint.
The greatest advantage this provides is the blade fitting perfectly into the central point of a center head, sliding through it.
Protractor head
Protractor heads are widely used for measuring and examining angles between markings, edges, and surfaces. After fitting your blade with a protractor head, you can set any angle between 0 and 180 degrees. When used with center heads, protractor heads allow for finding central points and marking accurate angles from the main point.
This head can also directly transfer angles, minimizing measurement errors and uncertainties, just like a bevel gauge.
Factors To Consider With Combination Squares
This section is all about the indispensable features you should consider before making any purchase. Missing a single one of them may cost you your chance at achieving woodworking perfection.
Materials
The materials used reflect the quality of anything made, and if you are seeking a long-lasting combination square, good materials should be a special priority. The blade of a combo square is crafted either with stainless steel or hardened steel. Stainless steel has extreme rust resistance but is not as strong as hardened versions. On the other hand, hardened steel is much less likely to prevent rust and corrosion.
That’s why stainless steel is so prevalent in the market; however, if you want to opt for hardened steel, make sure it is chrome plated, providing resistance to rust and ensuring durability.
Most of the materials used for constructing combination squares are cast iron, high-impact polystyrene, and die-cast zinc. Plastic tools are also available and sold at a low price, but they keep degrading with time, especially when exposed to high temperatures. Die-cast zinc is in heavy demand because of its usefulness in preventing rust and maintaining accuracy. Premium combination squares fabricated with cast iron are the king of durability but need to be cleaned after each use to prevent rust.
Blade size
Combination squares might all come in one shape but they do have different sizes to choose from. The most common sizes are 4 inches, 6 inches, 12 inches, 16 inches, and 24 inches. Several sizes are the perfect backup to any situation and 12-inch combination squares offer the greatest versatility if you have to choose just one.
Markings
Most combination squares have metric and imperial markings etched on their surface. Different models of blades have graduation between 10R and 4R. However, blades with 4R graduation are an excellent fit for detailed markings of ⅛ inch, 1/32 inch, 1/16 inch, and 1/64 inch. Blades with 10R graduation have equal divisions of 1/10 inch.
Readability
Markings play a massive role in maintaining the longevity of a combination square. Painted markings are clear to read initially, but fade with general wear and tear. Measurements can become unclear over time if the square’s markings were etched by the same machine used for cutting its blade.
Etched machine markings are carved inside blades and won’t fade away quickly. Therefore, these markings are the best possible option for getting precise, clear, and reproducible readings.
Versatility
Combination squares are considered versatile woodworking tools because of their interchangeable heads. The standard head coming with any combination square is a “square head”. However, you can switch to a protractor head or a center head based on your project’s requirements.
If you’re working on a complex job requiring all these heads, it’s a good idea to purchase a sturdy set of combination squares. Plus, several models offer a spirit level and a scriber, offering even greater convenience and accuracy.
