What is the Black Diamond on a Measuring Tape for?

Unless you use a measuring tape daily, you may have never even noticed those small diamond-shaped details on the top scale. And, even if you have, we bet that you only have the best guess as to what they might mean.

That’s why we’re going to set the record straight regarding these unique features. When we have to make something, we measure it using a ruler or a measuring tape, so that we get the precise or quantified outcomes.

And when we look back, we see that measurements have played a major role in history as well, it has helped ancient civilizations build, trade and create. But have you ever thought about who came up with the idea of measuring tape?

Early on there were different ways to measure things like at first the human body was used for measurements i.e. the width of the thumb was an inch, a foot for foot, and man’s belt as yard.

Moving on we see there was a wooden ruler, measuring wheel, we see that tools for measurements changed but the real game-changer was steel measuring tape.

In 1821, James Chesterman of England, created the design of measuring tape which was later on improved by Alvin J. Fellows provided more flexibility to the design and was later patented in the US. Later as we advanced the designs were further improved.

Hence measuring tape is a device that is portable and easy to quantify the size of different things whether it is used in tailoring, carpentry, etc., or to measure distance. For further precision and accuracy, it comes with different markings.

Almost all tape measurements have the usual number series around at least one edge of the tape. Tape measures usually have both metrics i.e. centimeter, meter, and imperial units i.e. inches, feet, and while measuring it can help us in such a way that if we are seeing something in inches, we can find out a metric equivalent of it and hence can learn both the systems.

There are versions that have markings that cover truss lengths for roofing and stud intervals for housing. Now when we take a deep look into tape measures, we see that there are different black diamonds or triangles on your measuring tape, ever wonder what that is for?

House design in USAThe center to center. Black Diamonds represent the middle of the studs. At the 19.2-inch mark comes the center of the first stud.

So what is this black diamond for?

The black diamonds which appear every 19 3/16” (19.2 inches) on metal measuring tape are for spacing I-beam “timbers.” Several wood-product manufacturers offer I-beam “timbers” as a substitute for solid lumber floor joists.

The diamond marks on tape rule blades are for spacing these engineered floor joists in new construction. Because these beams can support more weight than their dimensional lumber counterpart, they often have different spacing requirements.

Span tables for these beams provide ratings for spacings of 12”, 16”, 19 3/16”, and 24”. If you multiply these dimensions by 8, 6, 5, and 4, respectively, you’ll find each comes to 96”, the length of the plywood panels used for sub-flooring.

Those diamond marks are there for builders who want to take advantage of the great strength of engineered I-beams by using fewer floor joists, with no loss of floor support.

A standard concrete block chimney is two bricks by two bricks or roughly 16 inches square. That chimney won’t fit between studs that are installed on 16″- centers because there is only 14-1/2″ between the studs. However, “Black Diamond Spacing” is ideal because the space between studs at that spacing is 17.7″.

What is a stud?

Studs are boards that function as framing elements in your home, supporting the walls. You may wonder, how far apart are studs in my home? They’re always spaced either 16 or 24 inches on-center (measured from center to center) along the wall and run between the floor and ceiling. Drywall or lath (for plaster walls) attaches to the edge of the studs.

Many fasteners and hangers used to hang heavy objects, such as large pictures, mirrors, shelves, and television mounting systems, need to be anchored in studs because the wall alone isn’t strong enough to support the weight. Studs hold these fasteners better, preventing them from pulling out under the weight of the object. The center of a stud provides the best support for the fasteners.

How to locate a stud?

You can find studs with an electronic stud finder, or you can try to find them manually. If your walls are drywall, a stud finder locates studs quickly and accurately. It’s less effective on lath/plaster walls, but some have a metal-scanning feature that may locate the nails securing the lath to the studs. Several of the manual methods below are helpful if you have lath/plaster walls.

Whatever method you use for locating studs, make sure you find studs rather than objects such as pipes or conduits. When you suspect you’ve found a stud, locate multiple points on it to confirm that it runs vertically.

Locate several studs and measure between them to confirm they have typical wall stud spacing of 16 or 24 inches. If you get a different measurement, you’ve likely located something other than a stud.

Black diamonds are one of the hidden markings on a measuring tape. There are several similar markings on the measuring tape that have their specific meaning and motive. And, unless you’re a professional, you probably haven’t had too much use for them yet. Nevertheless, we think that some of these markings can be really beneficial, especially if you are working on a more heavy-duty DIY project. Some of these markings include:

  • Metric ad Imperial markings
  • Roman Numerals for accuracy
  • Year of Manufacture
  • Temperature and Tension
  • Testing Body
  • Length

Some other cool facts about measuring tape

Cool facts about measuring tapes

  1. Curve

The concave design helps keep the blade rigid when extended. This curve allows the blade to “stand out” while measuring and helping you read the measurement.

  1.  Nail grab

Tape Measure Nail Grab is on nearly every measuring tape, you’ll find a small slot on the end hook. It’s there to grab onto the end of a nail or screw.

This way, if you’re measuring a flat surface and don’t have anyone to hold the other end of the tape, you just need to hammer in a nail or insert a screw and hook the end of the tape onto it to get a clear and accurate measurement

  1. Red numbers

Many tape measures add red numbers (or some other graphical standout) every 16-inches, a very common spacing for studs in house framing.

This spacing allows for six supports in each 8-foot length. This spacing allows installing 8-foot-long sheets of plywood without cutting. Six supports can fit into an 8-foot space with 16” spacing.

  1. Scribing tool

At the end of the measuring tape, there is this tool that can be used for marking on the wall or the object by simply rubbing it on the surface back and forth.

  1. Tape housing

Very few people realize that your tape measure housing has its width printed on the back of the tape measure. This is very helpful when measuring inside a window or other areas where you may be confined.

All you need to do is add the width number to your measurement and you have an accurate measurement with half the hassle.

  1. Magnetic end

Most all new tape measures have a rare earth magnet at the end of the tape measure. This is useful for many situations like picking up a screwdriver or wrench. It also helps hold the tape measure in place to provide accurate readings.

Hence we see that new tape measures are designed in such a way that it is helpful for humans in every possible manner.

Frequently asked questions

  1. How suitable is this black diamond?

While the black diamond spacing is near as weight capable as 16-inch-centers building codes may not allow it in all situations. Also, the black diamond spacing does not place a stud at 48-inches so standard 8-foot sheets of plywood must be installed with the long dimension horizontal

  1. What is M on a measuring tape?

On many tapes (but by no means all) you will find a small red rectangle with the letter M printed inside followed by a number. The number simply denotes the year that the blade was stamped as conforming to the Measuring Instruments Directive. On the whole, this will also be the year in which that tape was manufactured.

  1. How many mm means 1 inch?

1 Inch is equal to 25.4 millimeters (mm). To convert inches to millimeters, multiply the inch value by 25.4.