Accurate measuring can save time and money on work like installing shelves, replacing a pane of glass or buying window shades.
To measure accurately, start with the right tools. Basic measuring and layout tools like rulers, tapes and squares are easy to use and should be in every toolbox.Start with a basic shop or bench ruler. Rulers are available in lengths from 6 to 48 inches. A 12-inch length is probably the most convenient. Rulers can come in wood or plastic, but a steel ruler is thinner, more durable and makes it easier to mark the work. It can also be used as a straightedge with a utility knife.
Often artists' stores carry a larger selection of rulers. They vary in length, thickness and flexibility. Some have rubber or cork backing to prevent sliding.
The classic carpenter's ruler is the folding wood rule. Carpenters preferred that to steel tape, because it remained rigid when extended and could measure wide openings like stairwells. For internal measurements like the interior width of a drawer the folding ruler has a brass slide rule in the end section.
The "push-pull" steel tape is a flexible, spring-loaded steel ruler that rolls into a small case. Tapes come in 3/8-, 1/2-, 3/4- and 1-inch widths from 8 to 30 feet long. Generally a 20-foot tape is the most practical. The 3/8- and 1/2-inch widths are more compact and easy to carry conveniently in the pocket, but the tapes do not stay rigid when extended any distance. The wider blades remain rigid without support, but they are often bulky. Buy a tape with a blade lock and a power return.
A good tape measure has a sliding hook at the end of the blade. The hook grips the end of the work and holds the blade as it extends. When making internal measurements, the hook slides into the blade and does not affect accuracy. With internal measurements it is important to add the case length, almost always indicated on the case. Tailor's tape measures may seem like a good substitute for steel tape, but they stretch after frequent use and can be inac-cu-rate.
Check joints and surfaces for squareness, and draw lines for right-angle cuts. Squares are the tools used for obtaining true right angles.
Traditionally, the try square has been the cabinetmaker's tool of choice for laying out right angles. It consists of a blade and a handle, riveted together in a fixed position. The handle is thicker than the blade and is placed against the edge of the work. The blade extends across the face of the work at a right angle to the edge.
The combination square is more versatile. It consists of a blade, a 12-inch steel ruler and a head that can slide in a groove along the blade. The head has two faces. One is perpendicular to the blade and is used to draw right angles. The opposite face is at a 45-degree angle to the blade and can be used to lay out miter cuts.
The combination square can also be used as a marking gauge to draw lines parallel to the edge of a board. That is useful if you want to rip the board, or cut it along the grain, to make it narrower.
To mark a parallel line, place the 90-degree face of the head against the edge of the board. Adjust the blade to the desired projection from the edge, and lock it in place by turning the lock nut on the head. Place a pencil at the end of the blade, and hold it there as you pull the square down the length of the board. As the square slides down the edge of the board, the pencil, held at the end of the blade, will draw the line.
The carpenter's, or framing, square is another useful tool. The square consists of two arms, the tongue and the blade, both marked with numerical graduations in inches and fractions. Because the square is cut from a single piece of steel, it has uniform thickness and will lie flat. That allows you to lay out large patterns in the centers of countertops, plywood or wallboard.
For angles greater or less than 90 degrees, the T-bevel, or sliding bevel, may be ideal. The bevel consists of a handle and an adjustable blade. To set an angle on the T-bevel, place the handle at the base of a protractor.
Slide the blade around so it intersects through desired angle gradation on the protractor scale. Lock the blade in place by turning the lock nut in the handle. The angle is now set, and you can easily transfer it to your work piece.