O-Rings & Industrial Sealing Solutions
O-Ring Supply Co. ships factory-direct o rings in NBR, HNBR, FKM, EPDM, silicone, PTFE and FFKM. Standard AS568 and metric sizes plus custom o rings, backup rings, kits and non-standard sealing support. 10,000+ sizes, MOQ 1 piece.
ISO 9001 Certified
Quality management system
RoHS & REACH
Environmental compliance
7-15 Days Lead Time
Express 3-5 days available
MOQ 1 Piece
No minimum order quantity
Real Factory
Manufacturing, inspection, and process control under one roof
These are actual workshop and process visuals from our production environment. For engineers and buyers, this is what reduces risk: visible manufacturing capability, visible process discipline, and a team that can support custom sealing requirements.
Workshop Operations
Active shop-floor production for molded sealing parts and custom orders.
Process Visibility
Clear manufacturing flow helps buyers validate consistency, lead time, and production readiness.
Select Your Material
Choose from our five premium materials, each engineered for specific industrial applications
Nitrile Butadiene Rubber
-40C to +120C
Excellent oil and fuel resistance
Hydrogenated Nitrile Butadiene Rubber
-40C to +150C
Excellent oil and fuel resistance
Fluorocarbon Rubber (Viton)
-20C to +200C
Exceptional high-temperature resistance
Ethylene Propylene Diene Monomer
-50C to +150C
Excellent weather and ozone resistance
Silicone Rubber
-60C to +230C
Extremely wide temperature range
Polytetrafluoroethylene (Teflon)
-200C to +260C
Widest temperature range of all elastomers
Perfluoroelastomer (Kalrez / Chemraz)
-15C to +325C
Widest temperature range of any elastomer
Polyurethane (AU / EU)
-35C to +80C
Excellent abrasion and wear resistance
Chloroprene Rubber (Neoprene)
-40C to +120C
Good weather and ozone resistance
Tetrafluoroethylene Propylene (FEPM)
-5C to +230C
Excellent steam and hot water resistance
Fluorosilicone Rubber
-60C to +175C
Widest temperature range of any fuel-resistant elastomer
Isobutylene Isoprene Rubber (IIR)
-40C to +120C
Lowest gas permeability of any elastomer
FEP / PFA Encapsulated Silicone / FKM
-60C to +260C
Virtually universal chemical resistance
Polyacrylate Rubber
-25C to +150C
Excellent automatic transmission fluid (ATF) resistance
Engineering Tools
Compression Calculator
Calculate optimal compression rate for static and dynamic seals. Ensures proper groove design.
Use CalculatorMaterial Selector
Find the right material based on temperature, media, and application type. Step-by-step guidance.
Find MaterialChemical Compatibility
Check compatibility of all 5 materials with 50+ industrial chemicals. A-D rating system.
Check CompatibilityIndustries Served
Proven sealing solutions across critical industries worldwide, from standard replacement sizes to custom-engineered sealing requirements
Industries We Serve
Specialized sealing expertise for demanding applications
Oil & Gas
FKM and FFKM seals for sour gas, HPHT downhole tools, and wellhead equipment. NACE MR0175 compliant compounds with full traceability.
Hydraulics
NBR, HNBR and polyurethane seals for cylinders, valves and pumps. Groove design support and failure analysis included.
Food & Beverage
FDA-compliant EPDM, VMQ and PTFE seals for CIP/SIP processing. Peroxide-cured compounds with taste-and-odor certification.
Pharmaceutical
USP Class VI silicone and EPDM for bioreactors, sterile filling, and autoclave cycles. Full extractables documentation.
Technical Capabilities
Engineering resources and manufacturing capabilities that support your sealing projects
Material Selection Engineering
Our engineers provide material recommendations based on temperature, fluid chemistry, pressure, and motion type. We validate selections against ASTM D471 immersion data and field performance records.
Custom Mold Fabrication
In-house CNC mold shop produces tooling for any inner diameter and cross-section. Standard circular profiles incur no mold fees. First-article samples ship in 3–5 days.
Dimensional Verification
Every batch is checked for Shore A hardness, inside diameter, and cross-section against AS568 or ISO 3601 tolerances. Optical measurement and batch certificates are standard.
Failure Analysis & Root Cause
We analyze failed seals to identify extrusion, compression set, chemical attack, or spiral failure. Reports include corrective recommendations for material, groove design, or operating conditions.
Latest from the Blog
Material comparisons, application guides, and sizing advice for engineers and buyers.
Hydraulic Cylinder Leaking at the Gland: Rod Seal Diagnosis
Hydraulic cylinder leaking at the gland? Follow the diagnosis: trace the weep, inspect the rod chrome, read the seal stack, then reseal with the right material.
How to Identify an O-Ring Size from a Worn or Old Seal
Learn to identify O-ring size from a worn or swollen seal: clean it, avoid four measurement traps, read OD and CS, then match the AS568 or metric size.
OEM vs Standard O-Rings: 3-Step Test to Tell Them Apart
OEM vs standard O-rings: a 3-step test using ID and CS measurements, AS568 and DIN 3771 size tables, and tolerance checks to decide catalog vs made-to-drawing.
Why Choose Us
Factory Direct Pricing
We manufacture every O-ring in-house. No middlemen, no markups - you get competitive pricing backed by 20 years of production expertise.
Full Material Range
NBR, FKM, EPDM, Silicone, PTFE and FFKM available from a single supplier. All materials meet international standards including FDA, RoHS and REACH.
Custom Sizes Accepted
We support both standard catalog sizes and non-standard dimensions. Submit your drawing, sample, or required dimensions and we will confirm feasibility within 24 hours.
No Minimum Order Quantity
Order as few as 1 piece for prototyping or emergency replacement. We support engineers at every stage - from R&D to full production runs.
Fast Delivery
Standard lead time 7-15 days. Express service 3-5 days available for urgent requirements. Global shipping via DHL, FedEx and sea freight.
Technical Support
Our engineering team provides material selection guidance, groove design review and failure analysis. We are a technical partner, not just a supplier.
Frequently Asked Questions
What is an o ring?
An o ring is a toroidal elastomer or PTFE seal that sits in a machined groove and seals by compression between two mating surfaces. It is the most common static and dynamic seal in fluid power, automotive, aerospace and industrial equipment. Browse our O-ring products, rubber o rings by material, or use the size chart to find standard sizes.
What O-ring materials do you supply?
We supply standard and custom O-rings in NBR (Nitrile), HNBR (Hydrogenated Nitrile), FKM (Viton), EPDM, VMQ (Silicone), PTFE and FFKM (Perfluoroelastomer). We also manufacture PTFE backup rings, special profiles, and custom O-ring kits for maintenance and MRO.
Where can I buy high-quality O-rings online?
You can request a quote directly through our website for standard AS568 and ISO 3601 sizes, custom dimensions, drawing-based parts, and material-specific kits. We ship globally with 7-15 day standard lead time and 3-5 day express options.
What makes a top-rated O-ring supplier for industrial use?
A reliable industrial sealing supplier provides ISO 9001 certification, full material traceability, conformance to AS568 and ISO 3601, dependable support for both standard and custom parts, and engineering help with material selection and failure analysis.
Which O-ring brands and materials are best for automotive applications?
NBR 70-90 Shore A is the best O-ring material for automotive engine oil, fuel, and brake systems. FKM is specified for fuel injection, turbochargers, and high-temperature engine seals due to its superior heat and fuel resistance.
What is the minimum order quantity?
We accept orders from 1 piece. There is no minimum order quantity for standard sizes. Custom sizes may require a small setup quantity - contact us for details.
Can you manufacture non-standard O-ring sizes?
Yes. We manufacture O-rings to custom inner diameters and cross-sections, and we also support special sealing profiles for OEM and replacement applications. Provide your dimensions, drawing, or sample and we will confirm tooling and pricing within 24 hours.
Which international standards do your O-rings conform to?
Our O-rings are manufactured to AS568, ISO 3601, DIN 3771 and JIS B 2401 standards. Material certifications include ISO 9001, RoHS and REACH compliance.
How do I select the right O-ring material?
Select O-ring material based on operating temperature, fluid media, pressure, and whether the seal is static or dynamic. Use our Material Selector tool for an instant recommendation, or contact our engineering team for a detailed review.
What is your delivery lead time?
Standard lead time is 7-15 business days. Express production and shipping (3-5 days) is available for urgent orders. Contact us with your requirements and we will confirm the fastest available option.
Need a Custom O-Ring?
Standard sizes, custom dimensions, and drawing-based sealing parts. Get your quote within 24 hours.