Pi Tape® Diameter Measuring Tapes
The periphery tape provides a quick, accurate and easy method of reading true diameters of both round and out-of-round forms.
information | specials | how to read
- Perfect for measurement of thin or soft walled parts - large
- Pi Tape gages consist of a narrow metal ribbon bearing special
These graduations are designed to convert circumferential distance into diameter measurement so the observer can read the diameter directly from the scale.
- Tapes are checked over master gages at .001'"(.03mm)
accuracy for standard tapes up to 144" (3600mm).
Certificate of accuracy traceable to National Institute of Standards and Technology is furnished.
- Pi Tape gages are a precision tool made of 1095 clock spring
steel (on request 420 stainless steel - for use in a corrosive
They require a minimum of maintenance, but we do recommend a quick wipe with an oil moistened cloth after use. A light gun oil works very well.
Make sure the tape has not been dented or kinked. This may
affect the accuracy of the tape.
Pi Tape gages are invaluable tools to the aero-space field as well as the plastic pipe industry. The variety of uses are infinite.
In stock... tapes ranging from 3/4"-7" to 132"-144" diameter available for same day shipping.
To Read Outside Diameter Tapes
How to use the tape
TAPES GRADUATED IN INCHES
TAPES GRADUATED IN MILLIMETERS
Each line on the Gage Member of the tape represents
.5mm of Diameter, while each line on the Vernier represents .01mm.
The zero on the Vernier is past the 661.5 line on the Gage Member
of the tape. Now find the line on the Vernier which corresponds
exactly with the line above. The example shows it to be the 23
line which equals .23mm. This added to the 661.5 reading gives
an outside diameter of 661.73mm.
When reading the OD tape, apply a snug pull of 2.25kg. tension, first making sure the tape and part have been properly cleaned.
Inside diameters can be read in the same manner by adding double the tape thickness to the reading using the standard outside diameter tape ( 0kg tension). Standard tapes are .25mm thick; thus .50mm would be added to the reading. It is suggested that direct I.D. tapes be used for Inside Diameter readings.
As a suggestion for checking very large diameters-pieces of masking tape may be used to hold the tape in proper parallel position.
When not in use, wipe clean and apply a light rust preventive oil. Store in tape container.
No periodic adjustments are needed.
Make sure the tape has not been stepped on or kinked, which may destroy the accuracy.