scales, but you will only need to use one of them for a particular drawing. Let’s make one example. Take a look at the w906a Architects Scale Lufkin Tape. It has 2 scales. One is 1/8 and the other is 1/4. Let’s say that the drawing in front of you is drawn to the 1/4 scale. It says this in the information box at the bottom. The 1/4 means that 1/4 inch on the drawing represents 1 foot in real life. In this case we will ignore the 1/8 scale and use only the 1/4 scale. Set your zero mark at the corner of some part of the drawing. The other corner is even with the 9 mark. That means it is 9 feet long. It’s really that simple.
Most of the pocket diameter tapes are 6 feet long. But the length isn’t really what they are all about. They are not designed to measure length. They measure diameter by wrapping them around the pipe circumference. See answer 4 for a more specific answer.
These tools make it easy for you. You wrap them around the pipe and read off the diameter.
These are pocket tapes. Their size makes them convenient, but they are not traceable to the NBS.
They can measure up to 23 inch diameter pipes. Some go as high as 38 inches in diameter.
Production time is about 3 weeks after you approve a proof.
Vector art is the best for this process. That means an eps or ai file are recommended. If you have other types of art, we can convert them.
The inch ones are calibrated to 100ths of an inch, 64ths of an inch, or to one millimeter.
Pi-Cobra tapes are made in China. The Lufkin ones are currently made in Mexico. All are imprinted in the USA.
Why do you need to choose a diameter tape, anyway? Because you want a quick and easy way to take a tape measure out of your pocket and find the diameter of a pipe or other round object. The best pipe diameter tape measure for your job can be solved by asking these questions:
Metric or inch, or both? Some tapes are marked in any of these 3 different scales.
Does a brand name matter? Lufkin tools have made a name for themselves. Pi-Cobra tapes are made in China, but they are less expensive, and longer.
What accuracy do you need? The pocket sized ones are quick and convenient. They are accurate to 0.01 inch. If you need a highly accurate one, check out Pi Tape. They cost about 10 times as much, and they can’t fit in your pocket. But here is their accuracy: Pi Tape metric tapes have a diameter accuracy of ± 0,03 mm up to 3 600 millimeters. Pi Tape inch tapes have a diameter accuracy of ± 0,001″ up to 144 inches.
PI Tape 24″ to 48″ Range Periphery Tape Measure ‑ 57‑065‑856
A tape measure can solve basically one problem….How long is the item? But a pipe diameter tape measure can solve a short list of problems for you.
What is the outside diameter (OD) of that pipeline, without having to cut into it. You don’t even have to divide by pi.
What is the diameter of a tree trunk.
What is the accurate diameter of a tire.
What is the diameter of a beach ball, when fully inflated.
Even if the pipe is distorted, and the cross sectional diameter would be different in different directions, you can do it. The pipe diameter tape measure can tell you what the diameter would be, if it weren’t distorted. That’s because the measurement is based on the circumference. The tape automatically divides by pi (3.14159) for you.
Keep it clean. If you keep sand and dirt from inhabiting your tape, it will look good longer and last longer.
Line it up straight on the pipe. If you put the tape on a little crooked, you will get an erroneously high reading.
Clean the pipe. This makes sure that surface contaminants aren’t interfering with your measurement.
Use a felt tip marker to mark common measurements directly on the tape. Don’t be a hero. This tip will make your job easier.
Put your name on it. Valuable and handy tools have a way of walking away.
Buy only the best pipe diameter tape measure. Lufkin is a trusted brand name.
Keep one in every location that you work (and leave it there). I keep one in the office, my shop, my tool box, and in all my vehicles and boat. A diameter tape doesn’t measure only diameters. The other side is a regular inch tape (or metric tape). So it comes in handy many times.
Please post your own tips in the comments here. I’d be interested in what you come up with. Thanks.
Diameter tape measures are made for wrapping around pipes and poles, to find the diameter. That’s a good enough reason to keep one in your tool box, garage, and vehicle. But there’s one feature that no one talks about, until now….
The other side of the diameter tape measure is a regular tape measure, in inches or centimeters. It measures length, not diameter. So, even though it is a special tape, it is also a handy every day tape, too. Lufkin, and the other manufacturers, thought of everything when they designed these handy pocket tapes. Everyone should have one or two.
Pi Day is March 14. This year you can help celebrate by answering the question at the bottom.
Pi is the constant ratio of a circle’s circumference to its diameter, no matter what size the circle is. This is useful knowledge when you work with water pipes or oil or gas pipelines, and you need to replace part of it. You can measure the circumference and divide by pi. But there’s an easier way to do that.
Let a Lufkin Diameter tape measure do it for you. You just wrap it around the pipe, and read the diameter. Mathematicians call pi an irrational number, since it goes on for an infinite number of decimal places, but using a diameter tape is a very rational and easy way to find the diameter of a pipe. To see a little video on How to measure the diameter of a pipe, just click here.