How to choose a square: fixed, adjustable or sliding bevel

To mark out and check right angles a fixed square is enough; to take an existing angle and transfer it to another piece you need an adjustable sliding bevel. In the collection the length ranges from about 85 mm to 1220 mm: the small squares (110, 180, 300 mm) are for carpenters and joiners, the long ones for sheets and large surfaces. The material (steel, aluminium, stainless steel, wood) determines how long it lasts and how accurate it stays.

Types

• Carpenter's square: sturdy, graduated, for marking out on timber and beams. The collection includes the Stanley FatMax Quicksquare 110 mm, the 180 mm and the 300 mm, as well as the graduated square 1-45-530.
• Joiner's square: for marking out and checking the right angle on wooden workpieces, like the 1-45-686 or the 1-45-685.
• Sliding bevel: the blade is adjustable and locks with a screw; it is used to take an angle and transfer it. One example is the Stanley Pro adjustable sliding bevel.
• Multi-function square: combines several functions in a single tool, like the multi-purpose square Stanley 2-46-017.
• Flexible square and mini square: the first adapts to uneven surfaces, the second fits into tight spaces.
• Long squares: in the collection they go up to 1220 mm, for checking squareness over large surfaces.

How to choose by job

The features to look at

Length. In the collection you will find from 85 mm to 1220 mm. Common sizes for marking out are 250-310 mm; above 600 mm you enter the site squares and those for sheets.

Material. Steel and hardened steel to last; stainless steel where there is moisture; aluminium for a lighter tool; wood for joinery work. For flexible squares, spring steels are used, such as flexible hardened steel.

Fixed or adjustable. A fixed square is more accurate and sturdy; an adjustable one does more jobs, but has a screw to keep an eye on.

Double face. Some product pages indicate a double face: the tool can be used and read from both sides, handy if you work from both the right and the left.

Finish. Anodised, painted, galvanised: it protects against rust and wear.

CE marking. It appears on some models; check the product page if you need it.

Common mistakes

• Not checking the accuracy. Draw a line, flip the square over and draw it again: if the lines don't coincide, the square is no longer at 90 degrees.
• Using it as a lever or a hammer. It bends and loses its angle.
• Taking a square that is too short. The angle error grows on large pieces.
• Marking out with a thick point. A thick pencil distorts the measurement: use a thin pencil or a scriber.
• Buying an adjustable one when a fixed one is enough. If you only need to make right angles, the fixed one is more reliable.

Frequently asked questions

What is the difference between a square and a sliding bevel?

A fixed square has a 90-degree angle. A sliding bevel has a movable blade that locks with a screw: it is used to take and transfer any angle.

How do I check that the square is true?

Draw a line along the long side with the square resting against a straight edge, then flip it over and draw again: if the two lines don't coincide, the square is out of true.

Which is better, steel or aluminium?

Steel is sturdier and withstands knocks better; aluminium is lighter and does not rust.

Can I mark out and cut with the square?

Rest the stock firmly against the edge of the piece and mark along the blade with a pencil or scriber. For cutting, use the square only as a marking guide and not as a rest for the cutter blade, which damages its edge.

Which one for tiles?

A long steel or aluminium square, to check squareness over large surfaces.

In the Squares collection you will find fixed, adjustable and multi-function squares from various brands; for advice on the right model or for a quote, ask the AMES technicians.