Carpentry Tips: Using Different Kinds of Measuring Tools

You need to use a measuring tool when doing carpentry projects. Once you’ve chosen your materials, you’ll have to measure and mark them for cutting. For this, you’ll need a measuring tool, a straightedge, and something to mark with. The ultimate success or failure of your project can be determined at this stage. Here’s how to ensure success.

Getting a project off on the right foot depends on careful measuring. Tight-fitting joinery for fine cabinets demands measuring and cutting to within 1/32″ or 1/64″. Less critical bookshelf boards and pieces can be cut to within 1/16. For rough measuring, you can use a wooden yardstick or ruler. For more precise work, use a metal tape measure, a metal yardstick, or a square’s blade. Whenever possible during construction, use one material to transfer measurements to another. No matter what tools you use, measure twice and cut only once.

Steel Tape Measure

For longer measurements, use a flexible steel tape – the longer and wider, the better. A tape measure’s end hook should be riveted loosely, so that it will adjust for precise “inside” and “outside” measurements. The case should be an even 2 or 3 inches long for accurate inside measurements. Most tapes are marked at 1/16″ increments, accurate enough for shelving.

Bench Rule

The bench rule is a standard steel or wooden rule 1″ to 2″ long. It usually has increments of 1/8″ marked on one side and 1/16″ on the other. The bench rule is convenient for short measurements, and it provides a firm straightedge to mark against. For greatest accuracy, measure from an “inside” mark, not the end.

Combination Square

The blade of a combination square excels for making precise, short measurements. The versatility of this tool offers several bonuses. If you don’t own a combination square, consider buying one. It could be one of your most useful tools.

Carpenter’s Square

Normally a carpenter’s framing and planning tool, the 16″ by 24″ square is great for laying out lines and checking for square when a combination square is too small.

Sliding T-Bevel

For marking 90^o or 45^o angles across a board, use a combination square. For other angles between 0^o and 180^o, use an adjustable T-bevel, commonly used for transferring fixed angles from piece to piece. Its blade can be set for any angle with the aid of a protractor. Some T-bevels have angles marked on the face.

Compass or Wing Dividers

A simple, schoolroom compass works for limited measuring jobs. It also draws circles or arcs. Wing dividers are more precise but cost more. They have a knurled screw that holds the legs in place. Use them to transfer small measurements or to step off equal marks. For large-scale curves and circles, tack one end of a thin board or yardstick to the material, hold a pencil against the board at the desired radius, and pivot.

Laying out most projects will require drawing lines – some straight, some curved, some at a particular angle. The first tool you’ll need for this is a pointed scribe, a sharp utility knife, or a good sharp pencil. A scribe or knife marks a more precise line, but the mark it leaves cannot be erased; a pencil can.

Some marking tips: For accurate lines and markings, tilt the pencil so the lead is as flush as possible against the straightedge. When measuring a board for a cut, first mark, then draw the line so the thickness of the line lies outside the measured area. To transfer irregular outlines to a board, use wing dividers or a compass.