T-squares are used in technical drawing, which is also known as drafting. Technical drawing requires precise drawings and T-squares are an essential drafting instrument. T-squares provide the foundation from which good renderings are created. T-squares are also used in the construction trade.
Make the distinction between the T-square used for technical drawing (such as architectural plans) and the T-square used for construction. The technical drawing T-square is used by professionals like engineers, draftsmen and architects. It is used along with a drawing board, whereas the construction T-square is used by bricklayers, carpenters and home builders.
T-squares are movable straightedges. T-squares are used to hold other tools such as squares and triangles. Place the T-square at a right angle to the edge of the drawing board. Slide the T-square up the surface of the table to the desired location on the paper.
Secure the T-square in place. T-squares should not slide around across the surface of the paper. On a slanted drafting table, T-squares are often mounted with a type of pulley system or that is mounted on both sides of the drafting table.
Use the T-square to draw parallel lines by simply tracing along its edge. Place squares and triangles on the T-square to precisely draw angles. "French curves" are used to draw curved shapes and templates are used to draw reoccurring shapes.
Place a T-square at the edge of a wall or cabinet to determine the angle. Lay a T-square in a corner to establish if it the edges form a right angle. T-squares, along with a level, are used in bricklaying to keep the line true vertically.