Articles
Short, practical tips on selecting and installing O-Rings.
Freudenberg N888: Low-Temp Aerospace Nitrile O-Ring (70 Duro NBR)
Freudenberg N888 is a 70 durometer low-temperature nitrile (NBR/Buna-N) O-Ring for aerospace: flexible to -65°F, qualified to MIL-G-5514 and SAE AS5440, built to AS28775, MS28775, and MS28784.
O-Ring Certificates of Conformance: House CoC and Manufacturer's CoC
What certification comes with your O-Ring order: The O-Ring Store's House Certificate of Conformance on every order, the Manufacturer's CoC for aerospace and mil-spec, PPAP, and how to request each.
HNBR vs Buna-N Nitrile O-Rings: Same Fit, Longer Life
HNBR (Highly Saturated Nitrile) O-Rings drop into the same sizes as standard Buna-N and add higher heat, better wear, and longer service life. Full side-by-side.

How to Measure an O-Ring With Your Phone: Inside Olypsys® Measurement Accuracy
How Olypsys® measures O-Rings with a smartphone, what actually drives its accuracy, and why gasket measurement is right around the corner.

Five Ways to Avoid Early Seal Failure
Most premature O-Ring leaks trace back to a handful of avoidable installation mistakes.

How to Measure an O-Ring
Two dimensions, one common mistake, and when to measure the groove instead.

Choosing the Right O-Ring Compound
A three-question shortcut to narrowing down the elastomer you need.