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The results obtained through the use of this device have been consistent and repeatable in our evaluations. However, since a degree of user technique is required we cannot be responsible for specific results.


the orid®


How The ORID Works:

The ORID itself is a tube with a specific weight inside it. The weight falls a controlled distance. To determine an O-ring's rubber compound, place the O-ring on a stable table or surface. Place the ORID® over the O-ring and raise the weight all the way to the top of the tube (as far as it will go). Release the weight and let it drop onto the O-ring. It will bounce. The height of the first bounce will rise to one of the four calibrated ranges. The highest is EP (Ethylene Propylene). The next is Nitrile. The next is Kalrez®. The lowest graduation is Viton®. This indicates your rubber compound.


The ORID® 70-C will indicate the material composition of 100, 200, 300 and 400 series O-rings of 60 to 80 Durometer which are already known to be either Viton®, Kalrez®, Nitrile or EPDM. The O-rings must be within their rated shelf life and be unused and undamaged.



  • Verify an O-ring at moment of installation

  • Check for mislabeled O-rings

  • Verify new O-rings

  • Sorting applications

  • Differentiate between known O-rings

  • Sturdy stainless steel tubular construction is safe to carry in tool boxes

  • Pocket clip for easy access


Labeled Graduations

The height of the FIRST bounce indicates the O-ring:

  • Highest Graduation — EP ethylene propylene O-rings are compatible with most water based chemicals from -70º F to +300º F or -55º C to 150º C.

  • Third Graduation — NITRILE. Also known as Buna-N. These O-rings are good for most plumbing applications from -30º F to +225º F or -35º C to 105º C.

  • Second Graduation — KALREZ®. Also known as perfluorocarbon, compatible with most aggressive chemicals from 0º F to +600º F or -18º C to 315º C.

  • Lowest Graduation — VITON®. This composition is also called fluorocarbon. Viton O-rings are generally compatible with most petroleum based liquids from -15º F to +400º F or -26º C to 205º C.