Pi Tape® Diameter Measuring Tapes

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The periphery tape. exemplified by Pi Tape® brand tape, provides a quick, accurate and easy method of reading true diameters of both round and out-of-round forms.

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.




To Read Outside Diameter Tapes

How to use the tape

TAPES GRADUATED IN INCHES

Standard width is 1/4" gage member. 1/8, 3/8 or 1/2" widths also available - extra charge per tape. Vernier scale divides each graduation on tape body into 25 parts or .001 of an inch
Example:
In the illustration the divisions to the left of the Vernier zero are 20 inches plus 1 division, or 20.025. The 15th line on the Vernier coincides with a line on the Gage Member. This is added to the 20.025, making a total diameter reading of 20.040, which is the true diameter reading as measured on the outside circumference. When reading the tape, apply a snug pull of 5 lbs. tension, first making sure the tape and part have been properly cleaned. When using a standard O.D. tape on an I.D. surface, add double the tape thickness to the reading to arrive at the I.D. of the part (0 lbs. tension). It is suggested that direct I.D. tapes be used for Inside Diameter readings.
 
Instructions on how to measure with Pi Tape® Inch Outside Diameter tapes on YouTube
 
 
   

TAPES GRADUATED IN MILLIMETERS

Standard width is 6.35 mm gage member. 4.76, 9.53 or 12.70 mm widths also available - extra charge per tape

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.

   
 Instructions on how to measure with Pi Tape® Metric Outside Diameter tapes on YouTube
   


Care

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.


 

Specialty Items

link to special pi tape page

Specialty Items
SPECIAL DESIGN TAPES CAN BE MADE TO SUIT YOUR REQUIREMENTS.*
  • Tension Scales available for use with Pi Tape® gages
  • Extra Graduations
  • Longer tapes (Reels available for many sizes)
  • Wider or Narrower tapes
  • Tapes calibrated for direct reading of inside diameters
  • Tapes with Go and No Go Calibrations for inspection or production departments
  • Stainless steel Pi Tape® gages-diameters up to 108", in the following width: 1/4" gage member with 1/2" body
FOR LOW LIGHT ENVIRONMENTS, WE OFFER TWO EZ-READ STYLES:
  • White EZ-read: dark lines with white background (Best for small diameters. Not for use with chemicals)
  • Blue EZ-read: white lines with dark blue background (Best for large diameters. More fragile than standard tapes. Not for use with chemicals)
* Special design tapes are not returnable


May have one or more sets of ABC dimensions on one tape. Anytime "o" line falls between A B C lines part is within tolerance. The minimum diameter distance between lines is .004" (.12mm).

 




link to Pi Tape® Brand economy extended range diameter tapes these tapes have a range of 72",

an economical alternative when an accuracy of .01 is an acceptable tolerance.