Pro Woodworking Tips.com-Measuring devices and how to read them

Measuring Devices and How to Read Them

Measuring devices and how to read them

As a woodworker I tend to take some things for granted. That is to say things that were taught to me when I was very young, I kind of assume everybody knows, and maybe they do. But just in case, I figured it might be a good idea to go over it.

When I was taught how to measure something, I don't recall ever seeing a tape measure. Everything was measured with a wood rule. Generally, they were six feet long, with folding joints. These are still used, but not nearly to the extent they once were.

Now days everyone has a tape measure, or ten. They are very convenient, come in all different lengths and thicknesses, and clip neatly to your pocket, for instant access. It seems as though there's some sort of contest going on to see who can make the longest one. (size matters ?). I find a twenty five foot tape, that isn't extra wide to be most practical on a construction site, (for my taste the max tapes are too wide to hold comfortably).

In a cabinet shop, I prefer to use a sixteen foot one. This is due to the fact that the long ones at a jobsite are likely to get used to their capacity, while for cabinet making, most of our measurements are under ten feet. Once you go smaller than a sixteen foot tape, they tend to be made too small to hold easily, and a bit fragile.

We use a tape about eighty five percent of the time, but they do have their drawbacks. For example, after a while, the end tends to move a little too much. Used for measuring the inside of an opening, and then cutting a part for it, by measuring from the end of a board can result in a sloppy fit. I tend to hold the "dumb" end of the tape with my thumb, and pull it tight, when taking an inside measurement.

The other option would be to use a rule. These too, are available in various configurations. Some have a metal extension for inside measurements. Some are marked as inside read rules, while others are marked as outside read rules. See photo.

The second photo shows two metal measuring devices. The one on the left is a draftsman's square, the one on the right is a straight edge with measurements on one side, and a center measuring tool, on the other. This allows you to measure from a center point out, in both directions. This is a very handy tool.

If working with several measuring devices, it is a good idea to verify they're synchronised, or you could be in for a surprise. (often they are not going to read the same).

In the above photo you can see that the smallest increment of measurement on it is 1/16". (also the shortest line). Each line on the rule is an increment of that. The next line is 1/8". (or 2/16"). The third line, also a short one is 3/16". The length of the lines help to quickly determine if it's read as a multiple of a sixteenth, or an eight, or a quarter, and finally a half. Also note the "hook" on the end of the rule. (It folds in to be relatively flush with the edge of the rule). This is to allow easy measuring from the outside of an object. I rarely use it, but it's worth noting.

This method of line length makes it easy to find, say 9/16". Knowing that a half inch is equal to 8/16", it's a matter of going to the next sixteenth increment. I can't tell you how many times over the years, someone called out a measurement to me as, 1/2" plus one little line. I have to admit wondering who hired this "carpenter", and why!