A sauterelle is a tool used to create, duplicate and measure angles. The name originates from French and translates as “grasshopper.” This may be related to the way in which the tool can resemble a grasshopper when viewed from the side. The use of the word sauterelle in other languages indicates the tool may be linked to masonry sauterelles used in the building of castles and cathedrals in Europe during the Middle Ages. A sauterelle may also be known as a T-bevel, bevel gauge or bevel square.
In its simplest form, the sauterelle consists of two straight edges, each rounded at one end; those edges are held together by a pivot at the rounded ends. When unfolded at a right angle, the tool has the “L” shape of a framing square, and may also be known as a false square. The pivot is commonly secured by a wing nut or other adjustable mechanism. This mechanism is loosened so the arms can be moved to the desired angle, then tightened so the angle can be copied to another object or surface.
Sauterelles do not have markings for determining the angle. Another tool, such as a protractor, is needed to measure specific angles. It is possible to use a linear measuring device, such as a ruler held perpendicular to the end of one of the arms, to calculate the angle. The math needed to do so may be considered too clumsy, however, given the common availability of protractors.
To create an angle, the sauterelle is placed on a measuring device such as a protractor and adjusted to match the desired angle. The sauterelle is then held up to the object to be altered. If the object to be altered is adjustable, such as a miter saw, the sauterelle may be placed next to the mechanism so it can be adjusted. The sauterelle can also be used to trace the angle on an item to be cut.
A sauterelle may be used to measure an angle by simply reversing the method for creating an angle. It is adjusted to match the angle that is to be measured and then placed against a measuring tool such as a protractor to determine the angle. This method may be useful if the measuring tool available cannot be used to measure the angle directly, such as a circular protractor and the corner of a room.
To duplicate an angle, the sauterelle is placed in or against the angle and the arms are adjusted to match. The sauterelle may then be used to make an adjustment on another tool, such as a saw, or to trace the angle to an item to be cut. This use is one for which the sauterelle may be better suited than any other tool, because it may allow irregular or difficult angles to be duplicated fairly easily. Examples include cutting trim for a room in a house that has settled or that simply was not built square in the first place.