Articles
Short, practical tips on selecting and installing O-Rings.
Chloranthraquinone O-Ring Compatibility: Which Compounds Hold Up
Chloranthraquinone O-Ring guide for dye intermediate and specialty organic synthesis: chart ratings, why FKM is the preferred start, and which elastomers to avoid.
IRHD Hardness Testing vs Shore A: Measuring O-Rings and Thin Sections
What IRHD means for O-Rings: ASTM D1415 / ISO 48-2 dead-load methods, Micro IRHD for thin cord and curved seals, why readings differ from Shore A (ASTM D2240), and how seal engineers use hardness.
Borneol O-Ring Compatibility: Which Compounds Hold Up
Borneol O-Ring guide for fragrance and specialty organics service: chart ratings, why FKM is the preferred start, and which elastomers to avoid with this terpene alcohol.
Isobutyl Chloride O-Ring Compatibility: Which Compounds Hold Up
Isobutyl chloride O-Ring guide for chlorinated solvent and alkyl halide service: chart ratings, why FKM is the preferred start, and which elastomers to avoid.
Low-Temperature Brittleness Testing: Impact Crack Points vs TR-10
What ASTM D2137 / ISO 812 low-temperature brittleness means for O-Rings: impact crack temperature, test sequence, how it differs from TR-10 cold sealing, family notes, and how seal engineers read the number.
Sulfur Trioxide Dry O-Ring Compatibility: Which Compounds Hold Up
Dry sulfur trioxide O-Ring guide for sulfuric acid plant and SO3 process service: chart ratings, why FKM is the preferred start, and which elastomers to avoid in dry SO3 duty.
Xylene O-Ring Compatibility: Which Compounds Hold Up
Xylene O-Ring guide for petrochemical and solvent service: chart ratings, why FKM is the preferred start, and which elastomers to avoid in aromatic hydrocarbon duty.
Ammonia (Anhydrous) O-Ring Compatibility: Which Compounds Hold Up
Anhydrous ammonia O-Ring guide for refrigeration and process service: chart ratings, why neoprene and EPDM lead, and why FKM is the wrong start for NH3 duty.
Benzene O-Ring Compatibility: Which Compounds Hold Up
Benzene O-Ring guide for petrochemical and solvent service: chart ratings, why FKM is the preferred start, and which elastomers to avoid in aromatic hydrocarbon duty.
Compression Set Elastomer Testing: Why Flattened O-Rings Stop Sealing
What compression set means for O-Rings: ASTM D395 / D1414 / ISO 815 methods, 0% vs 100% set, gland take-a-set behavior, polymer test temperatures, and how seal engineers use the number for long-term squeeze.
Lubricating Oils (Crude & Refined) O-Ring Compatibility: Which Compounds Hold Up
Lubricating oils (crude and refined) O-Ring guide for pumps, compressors, gearboxes, and lube skids: chart ratings, which elastomers to use, and which to avoid.
Lubricating Oils (Synthetic Base) O-Ring Compatibility: Which Compounds Hold Up
Synthetic-base lubricating oil O-Ring guide for compressors, hydraulics, and gearboxes: chart ratings, why FKM is the preferred start, and which elastomers to avoid or test.
TR-10 Elastomer Testing: How Temperature Retraction Predicts Cold Sealing
What TR-10 means for O-Rings and rubber seals: ASTM D1329 / ISO 2921 test method, how to read TR-10 and TR70, static vs dynamic cold limits, and typical values by elastomer family.
Precision Vulcanized O-Rings: Tolerances, Olypsys® Inspection, and why The O-Ring Store Does it Best
Why The O-Ring Store leads on precision vulcanized O-Rings: posted Class 2 and Class 3 tolerances, in-house splicing capacity, and Olypsys® Large Format inspection that proves large custom rings meet spec.
Butyric Anhydride O-Ring Compatibility: Which Compounds Hold Up
Butyric anhydride O-Ring guide for cellulose acetate butyrate, fragrance, pharma, and agrochemical service: chart ratings, which elastomers to use, and which to avoid.
Do O-Rings Expire? Here's the Straight Answer
Most O-Rings outlast the drawer they sit in. Here's how long each compound really keeps, what ruins them on the shelf and how to tell if an old one is still good.
Calcium Hydrosulfide O-Ring Compatibility: Which Compounds Hold Up
Calcium hydrosulfide O-Ring guide for leather dehairing, wastewater metal precipitation, and pulp service: chart ratings, which elastomers to use, and which to avoid.
Potassium Stannate O-Ring Compatibility: Which Compounds Hold Up
Potassium stannate O-Ring guide for alkaline tin plating baths: chart ratings, which elastomers to use around plating tanks, and which to avoid.
Para-Aminobenzoic Acid O-Ring Compatibility: Which Compounds Hold Up
Para-aminobenzoic acid (PABA) O-Ring guide for pharmaceutical and dye intermediates: chart ratings, which elastomers to use, and which to avoid.
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.
