The United States never did switch over to the metric system, as it was planned in the 1960’s and 1970’s. Yes, metric went over like a lead balloon. Americans are happy with inches, feet, gallons, and yards. The centimeter, liter and meter were mostly rejected. Both systems are used today in 2021 in labeling food products and liquids, but we Americans have learned to skim over those parts of the label that don’t fit into our familiar system.
The scientific community is firmly based on the MKS and CGS systems (meter, kilogram, second) and (centimeter, gram, second). The biggest part of the world is metric-based also.
Fortunately, pipe diameter tape measures are made for both systems, separately, and there is even one that is made with the inch and metric system together. The front side of the tape is in diameter inches (up to 38). The back side is in diameter millimeters (up to 955). This is a rare tool, but some companies need both measurements to satisfy their requirements.
The diameter tape measure easily figures the diameter of a pipe or pipeline. All you have to do is wrap it around the pipe, and read off the diameter. Here are its mysteries..
Why is the “zero” mark not at the beginning of the tape? It is a couple inches away from the beginning of the tape.
Why does the end of the tape have a “loop” instead of a “hook”?
Why are some calibrated in 100ths of an inch, and some in 64ths of an inch, and some in millimeters?
By having the zero mark away from the beginning of the tape, you can easily line up the other part of the tape to the zero mark.
Since zero is not at the end of the tape, there is no need to have a hook there. What is helpful, is to have a metal loop to hold onto, when wrapping the tape around the pipe.
Different strokes for different folks. Automotive repair people prefer the 64ths of an inch calibration. Oilfield people prefer the 100ths of an inch version. And of course, some people use the metric system of measurement.
The popular Barlow Chrome Tape Measure number 20217. Why this product? The Barlow tape is a household word in many USA homes. The Barlow brand has a proud history of quality. Simplicity in design makes for a long lasting product life. The dual scale, metric and inch, make it popular in any country. The smooth compact design makes it a great tape to keep in your pocket. Your company logo can easily be laser engraved on the front and back.
64ths or 100ths? This question applies only if you need the Inch version of a pipe diameter tape. If you are in the oil and gas industry, you probably prefer the 100ths calibration. If you are in the boat or automotive industries in the USA, you would probably prefer the 64ths of an inch calibration. If the SKU number has a “d” in it, this means it is calibrated in 100ths of an inch.
Size. The Lufkin models of the pocket diameter tapes will measure pipe diameters up to 23 inches. The Pi-Cobra models will measure pipe diameters up to 38 inches.
If you live in a non-metric country, you never know when you might need a metric tape measure. Since the economy is now a “global” economy, metric size bolts and other parts are appearing all the time. Here is a pocket tape for you. It is the only metric tape measure you will ever need. This is why:
It measures straight objects in centimeters.
It measures straight objects in inches.
It finds the diameter of round objects like pipes, in centimeters and millimeters.
It finds the diameter of round objects like pipes, in inches and hundredths of an inch.
It is small enough to fit in your pocket
It will hold your important car keys and house keys.
It can display your company logo on the front, and other info on the back.
This versatile tape is marketed by Diameter-Tapes.com. It is the most useful and rarest of all OD (diameter) tapes.