ORID O-ring Identifier


The ORID® O-ring Identifier

The ORID® O-ring Identifier performs a non-destructive field test of an O-ring seal to identify its rubber compound.

The ORID® O-ring Identifier itself is a tube with a controlled or specific weight inside it. The weight falls a controlled height or distance. Its sturdy stainless steel construction ensures it is safe to carry in tool boxes. Additionally it has a pocket clip for easy access.


Verification of an O-ring at moment of installation.
Check for mislabelled O-rings.
Verification of new O-rings.
Sorting applications.
Differentiate between known O-rings.


Place the O-ring on a stable surface and position the ORID over the O-ring. Raise the weight 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 and the height of the first bounce will rise to one of the four calibrated ranges. Highest is EP, next is Nitrile, followed by Kalrez®/FFKM, and the lowest graduation is Viton®/ FKM. This indicates the rubber compound.

The ORID 70-C will indicate the material type for 100, 200, 300 and 400 series.

O-rings of 60 to 80 Durometer which are already known to be either Viton®/FKM, Kalrez®/FFKM, Nitrile or EPDM.

The O-rings must be within their rated shelf life and be unused and undamaged.

The results obtained through the use of this O-ring Identifier 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 height of the FIRST bounce indicates the O-ring material:

Highest Graduation – EPDM

EP ethylene propylene O-rings are compatible with most water based chemicals from -70ºF to 300ºF or -55ºC to 150ºC.

Third Graduation – NITRILE

Also known as Buna-N. These O-rings are good for most plumbing applications from -30ºF to 225ºF or -35ºC to 105ºC.

Second Graduation – KALREZ®

Also known as perfluorocarbon, compatible with most aggressive chemicals from 0ºF to 600ºF or -18ºC to 315ºC.

Lowest Graduation – VITON®

This composition is also called fluorocarbon. Viton O-rings are generally compatible with most petroleum based liquids from -15ºF to 400ºF or -26ºC to 205ºC.


3 in stock (can be backordered)


If you have any queries or would like any more information, don’t hesitate to get in touch.