Measuring and Marking Linear Dimensions

Measuring from point ”A” to point ”B” is a simple process, but your results still depend on how accurately you are able to translate a measurement into a physical mark on a piece of wood. If you’ve ever tried to hold a tape measure flat on a board while you accurately mark off a measurement, you know that just getting a clearly defined mark in exactly the right spot can be a surprising challenge. For precise measuring and marking, the tool you use needs to be readable and, of course, accurately calibrated. Going beyond that, the best distance measuring tools offer a little help in getting the mark in the right place. Incra Precision Marking Rules are famous for their accuracy, lay flat, and have an easy-to-read scale. But what makes them the tool of choice for linear measuring is that they make it virtually impossible to put a mark in the wrong place. Incra rules are made with micro fine guide holes positioned at 1/32′ increments so that, used in conjunction with a mechanical pencil or a metal scribe, you’d really have to try hard to put a measurement mark anywhere other than exactly where it’s supposed to be. Special features of some tools further simplify one of the most common measuring tasks in woodworking – measuring and marking a distance from an edge. Tools like the Incra Precision T-Rule and Precision Bend Rule take care of positioning “point A” in the “point A to B” measuring formula while still offering the famous Incra accuracy and easy-to-use design. All that’s left for the woodworker to make a perfectly positioned mark at a precise distance from an edge is to get the scribe or mechanical pencil in the right guide hole and make a mark.
Measuring Squareness

The Crown try-miter square is especially handy because it also allows you to check and mark the second most common angle in woodworking – 45 degrees. A combination square takes that versatility and adds to it with a graduated scale and a blade that can be adjusted and locked into position to gauge depth or distance relative to the edge of a material. The combination square was borrowed from the machinist’s tool chest years ago, and because of its all-around usefulness, it remains the “workhorse” square in most woodworking shops.
Angles Other than 90 and 45 Degrees
90 and 45 degree angles may be the most common in woodworking, but they’re not the only ones that come up. For marking angles other than 90 and 45 degrees, most woodworkers use a sliding bevel, or ”T-bevel.” The T-bevel’s sliding blade is infinitely positionable and has the added benefit of giving you four possible handle-to-blade angle orientations when the tool is set up in the “T” shape (with some of the blade on either side of the handle). If you’re shopping for a T-bevel, it’s important to look for one that has a good lock down mechanism so that you don’t run the risk of accidentally moving the angle setting while you’re using the tool. This classic example by Crown with a rosewood body and steel blade cinches down more than well enough to hold a setting for as long as you need it to.
Measuring Angles

On the other hand, if you need an accurate measurement of an existing angle, you won’t do better than the Starrett Protractor / Angle Finder. The tool is calibrated to read both inside and outside corners and quickly gives you not only the angle of the corner, but also offers the correct miter setting for your saw. Starrett is one of the most trusted names in calibration and measurement tools, so you can be confident that the Protractor / Angle Finder’s precision matches its speed. A tool like the Starrett angle finder is an essential angle measurement tool for fitting your work into the real world, which, as anyone who’s ever installed cabinets, crown molding or any kind of trim will tell you, isn’t always laid out in perfect 90 degree angles.
Measuring Depth, Gap and Thickness
Often, woodworking projects require that you measure a short distance with extreme accuracy. Fine tuning the depth of a rabbet, checking the width of a dado and measuring the thickness of veneer or stock all call for a tool that will give you extremely precise short distance readings. For these necessarily finicky measuring tasks, you really can’t go wrong with a digital caliper. The digital caliper is the latest advancement in a precision measuring tool that migrated from the machinist’s tool kit into the wood shop years ago. They’re equipped with sets of jaws that measure inside and outside dimensions with accuracy in the 1000ths of an inch range, and a probe that slides down from the bottom of the tool to gauge depth with equal precision. Calipers are also available in models that have a dial readout and a standard calibrated scale, but the modern digital variety is so easy to use and read that most woodworkers find the slight upcharge for the feature well worth the price.
Source: http://www.rockler.com/skill-builders/measuring-and-cutting/marking-and-measuring-tool-basics