This forgotten child gives you the outside diameter of a pipeline in both inches
and centimeters. It is valuable to both Americans (using the inch system) and those who use the Metric system of measurements. It goes up to 38″ diameter (955 millimeters diameter). The only thing it doesn’t offer is the ability to measure straight objects. You would have to have a regular tape for that.
Who would use this tape? Inspectors who travel and deal with both systems. Any drilling companies that use both metric and imperial systems of measurement.
Lufkin® has a world-wide reputation for making high quality tape measures. They used to make them in the USA, but they have shifted the production facilities to Mexico. Some of the tapes are made out of a cast case, which is highly polished and chrome plated, like the w906pd. Others, like the w606pd have a stamped case, which is shiny and chrome plated. A third type of case is black plastic, like the asw616pd. However, the tape blade inside is the same in all 3 types of cases. It is capable of measuring diameters up to 23 inches.
Pi-Cobra is a brand name for diameter tapes made with
a cast case which is chrome plated. It can hold a longer tape blade, capable of measuring diameters up to 38 inches. The case is very durable. These are manufactured in China.
Various other Chinese manufacturers make versatile OD tapes like the 416-04-024-P. The back side of the tape measures diameter up to 24″ in 100ths of an inch or 610 mm. The case is plastic, and has a key ring attached to it.
The UT-56675 is made in the USA. It is capable of
measuring pipes up to 45 inches in diameter. This is a belt tape, not a pocket tape. The calibrations are in tenths of an inch diameter.
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.