Is My Tape Measure Accurate?
George VondriskaDescription
A tape measure, more specifically an accurate tape measure, is an essential tool for all woodworkers. George Vondriska teaches you a helpful tip to ensure your tape measure is accurate for both inside and outside measuring.
Tape measure is a very handy thing to have in the shop. It's great for figuring out how long you've been working. But, what you wanna do is make sure that the tape measure is doing everything it's supposed to do. And one of the things that tape measures do is they have these hooks on the end that float. And they're supposed to do that, that's fine. It compensates for inside and outside measuring. What we wanna do is make sure it's doing it correctly. So, it's a very easy process. I've got a steel rule here on the bench up on these blocks so that the ends are cantilevered. To do an outside dimension check, we're gonna hook on that end of the 24-inch rule and then simply read it on this end. Because it's a 24-inch rule, when we read on this end, we need to be able to align that 24 inch mark with the end of the steel rule. So that tells us that, for outside dimensions, it's okey and dokey. Now, for inside dimensions, I'm gonna put the ruler on the bench and I'm gonna put a block right on the 12 inch mark and clamp it in place. Then, just like you would do if you're taking an inside dimension, I'm gonna allow the hook or the tip to go against that block and then on this end, make sure that that 12 inch mark goes right to the end of the rule. If it does, then we know that you're ruler is accurate for both outside and inside dimensions and you can be sure that when you use it on your woodworking projects, it's giving you all the numbers that you need and should be getting 'cause it's doing it accurately. So it's worth, every once in awhile, making a check on your tape measure to make sure that it's accurate for both inside and outside dimensions.
I worked in a cabinet shop in 78' and the foreman had us check our tapes to the shop rule every Monday morning and adjust if needed. He was also a stickler about not letting the tape slap closed. He would rant about how it elongated the slots in the tape and in effect, ruin it causing inaccurate measuring and cutting. If he heard one of our tapes slap close and knew, who did it, he would make that person work the rest of day without it. You learn quick to catch the tape with your finger after trying to work without a tape measure for a day or so. It is second nature to me now and to this day when I hear a tape slap closed, even a little, as George did early in the video, it catches my attention. 😉
Tape measure accuracy should be checked, each time your rule slips from your belt and hits the floor. It’s not unusual that the end hook takes the hook, bending the hook, throwing out of accuracy.
Might be good to remind the folks that when your tape rule slips from you belt, it’s not unusual that when it strikes the floor, that it hits in the end tab, bending it. Subsequently causing an inaccurate reading. Good to each time it takes a big hit.
Both methods have possibility of inaccuracy. For an outside measurement, clamp the ruler so that one end is flush with a block, not cantilevered. This prevents the tape measure hook from wrapping under the ruler if its bent. For the inside measurement, press a block up against the end of the ruler so that the end of the tape measure and ruler are exactly aligned.
Another way to check your tape for INSIDE accuracy is to butt the end against the hook of a hook rule. You can then confirm that the tape's markings are in line with the hook rule's. If not, the tape is not good for inside measurements.
Also, make sure you use to use the same tap measure on all measurements
There is no video or audio:-(
Metal expands and contracts with temperature changes, and a tape measure can be of a length sufficient to suffer from the changes in length affecting accuracy due to temperature differences. ie outside in freezing weather, or inside in a heated house, but it probably wont be significant in most circumstances, though its worth remembering.
And what does one do if the tape measure is *not* accurate? One can bend the end tab only so much.