Articles
Short, practical tips on selecting and installing O-Rings.
EPDM NSF-61 O-Rings: Peroxide-Cured, Chloramine-Resistant Potable Water Seals
Buy EPDM FDA/NSF-61 peroxide-cured O-Rings for chloraminated drinking water, hot water, and food contact. Specs, approvals, and where this 70 duro compound belongs.
Ucon Lubricant 50-HB-260 O-Ring Compatibility: Which Compounds Hold Up
Ucon Lubricant 50-HB-260 O-Ring guide for PAG compressor, hydraulic, and metalworking fluids: chart ratings, which elastomers to use, and which lack data.
SAE J1926 ORB Boss O-Rings: AS568 900-Series Sizes That Actually Seal the Port
What SAE J1926 O-Ring Boss fittings need from the seal: AS568-901…932 boss O-Rings, how they differ from NPT and JIC, materials, install tips, and a Boss-only size chart.
The Master O-Ring Size Chart: What It Shows, Why It Helps, and Who It Is For
A practical guide to the handbook Master O-Ring Size Chart: multi-standard sizing, nearest-match search, tolerances, back-up rings, and who gets the most from it.
Calcine Liquors O-Ring Compatibility: Which Compounds Hold Up
Calcine liquors O-Ring guide for mineral processing and metallurgy: chart ratings, which elastomers hold up in aqueous calcination circuits, and which to avoid.
Ammonium Sulfite O-Ring Compatibility: Which Compounds Hold Up
Ammonium sulfite O-Ring guide for water treatment, pulp and paper, and photo chemistry: chart ratings, which elastomers to use, and which to avoid.
PTFE Backup Rings: Anti-Extrusion Retainers for Aerospace Hydraulic and Pneumatic Systems
Engineering reference for PTFE backup rings (packing retainers): extrusion mechanics, single versus double configurations, cut geometry, and the MS28774, MS28782, MS27595, AS5781 and AS8791 specifications.
Naphtha O-Ring Compatibility: Which Compounds Hold Up
Naphtha (petroleum solvent) O-Ring guide: which elastomers swell or fail, why FKM and nitrile usually win, and how to read the chemical compatibility chart for VM&P and solvent naphtha.
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.