O-rings - Reliable Sealing Solutions for Every Industry
O-rings are flexible, ring-shaped seals made from rubber-like materials that provide reliable sealing under pressure by deforming within grooves to block the passage of fluids or gases. Commonly used in hydraulic, pneumatic, and industrial applications, their elasticity allows them to maintain a tight seal even under varying temperatures and pressures.
Rhondama supplies an extensive range of industrial O-rings, from standard general-purpose rubber types to high-performance FFKM O-rings and specialised, AED/RGD compounds. Our materials are engineered to meet the most demanding certifications, including FDA-approved O-rings, USP Class VI, WRAS, and other industry standards. Thanks to our large inventory and fast shipping capabilities, we serve critical industries including aerospace, pharmaceuticals, food & beverage, semiconductor manufacturing, oil & gas and petrochemical.
Why O-rings?
O-rings are the most widely used sealing solution across industries due to their simplicity, adaptability, and excellent cost-to-performance ratio. These seals maintain tight compression under both static and dynamic conditions and are available in a broad range of elastomer materials to support:
- Chemical resistance
- Thermal stability
- Wear resistance
- Wide pressure and temperature ranges
Their compact design makes them suitable for applications where space is limited, and their reusability in certain setups further increases value. Rhondama’s O-rings are trusted in oil and gas exploration, medical devices, food-grade applications, automotive engines, and industrial pumps.
Choosing the Right O-ring
Selecting the right O-ring depends on several factors:
- Temperature range
- Chemical compatibility
- Pressure cycles
- Industry certification
- Dynamic vs. static sealing
Need guidance? Explore our Material Selection Guide.
O-ring Sizing and Globals Standards
We stock O-rings manufactured to internationally recognized O-ring sizing standards, ensuring global compatibility and easy replacement:
- AS568 (US)
- BS4518 (UK) Metric
- BS1806 (UK) Imperial
- JIS B 2401 (Japanese)
These standards cover: cross-sections, inside diameters, and material tolerances, helping engineers match groove dimensions precisely and avoid seal failure.
O-ring Certificates and Approvals
Rhondama supply O-rings in a wide range of grades and can be manufactured to meet specific industry approvals, making them suitable for use in demanding and regulated environments. These include certifications such as FDA for food contact,
USP Class VI for medical applications, WRAS for potable water, and various ISO and ASTM standards.In the oil and gas industry, where extreme temperatures, pressures, and aggressive chemicals are common, O-rings may require compliance with NORSOK M-710 or API 6A standards, ensuring high performance and reliability under harsh conditions. Choosing the right material grade and relevant approvals is crucial to ensuring safety, durability, and regulatory compliance in critical applications.
Material Comparisons
| Material | Common Temp. Range (°C) | Key Strengths | Limitations | Typical Applications |
|---|---|---|---|---|
| NBR | –40 to +120 | Excellent oil, fuel, hydraulic fluid resistance; cost-effective | Limited weather/ozone resistance | Automotive, hydraulic systems, general sealing |
| EPDM | –50 to +150 | Excellent water, steam, weather, ozone, polar solvent resistance | Poor resistance to oils & fuels | Water systems, food & pharma, HVAC |
| FKM | –20 to +200 (up to 250) | Broad chemical resistance, high temp stability | Limited at very low temps; higher cost | Automotive, aerospace, chemical processing |
| VMQ | –60 to +200 | Outstanding flexibility at low temps, biocompatibility, food-safe | Poor tear strength, limited chemical resistance | Medical devices, food processing, electronics |
| CR | –40 to +120 | Moderate oil, ozone & weather resistance | Superseded by better materials in many cases | Refrigeration, some legacy equipment |
High Performance O-ring Materials
FFKM O-rings, also known as perfluoroelastomers (ASTM FFKM or ISO FFPM), are the highest-performance elastomeric sealing materials available. They are engineered for extreme thermal and chemical environments, with continuous service temperatures typically ranging from –20 °C to +325 °C (–4 °F to +617 °F), and short-term excursions up to around 350 °C (662 °F). Certain formulations are designed to meet strict regulatory approvals, including FDA 21 CFR 177.2600, USP Class VI, and 3A sanitary standards, making them suitable for use in food, pharmaceutical, and biotechnology applications.
The main advantage of FFKM O-rings is their near-universal chemical resistance — withstanding strong acids, bases, amines, solvents, oxidizers, steam, and aggressive hydrocarbons—far beyond the capabilities of standard fluoroelastomers. In addition, they provide
excellent thermal stability, oxidative resistance, and low out-gassing, with very good compression-set resistance. This makes them highly durable in both static and dynamic sealing applications, particularly in semiconductor manufacturing, chemical processing, oil & gas, aerospace, and pharmaceutical industries where failure is not an option.
AED/RGD O-rings (Anti-Explosive Decompression / Rapid Gas Decompression) are specially engineered sealing elements designed for use in high-pressure gas environments such as oil & gas, subsea, and aerospace applications. Standard elastomers can blister, crack, or rupture when exposed to sudden pressure drops, as gas absorbed into the material expands too quickly. AED/RGD compounds are formulated with optimized crosslinking and filler systems that resist this decompression damage, ensuring longer service life and greater reliability in critical operations. These O-rings typically meet international standards such as NORSOK M-710 for rapid gas decompression resistance and often combine with broad chemical and temperature resistance depending on the base polymer (e.g., FKM, HNBR, or FFKM). The key benefit of AED/RGD O-rings is improved safety and performance under extreme pressure cycles, reducing seal failure risks and costly downtime in demanding
gas-handling systems.
Request a quote or contact us
Looking for industrial O-rings? Need guidance on FFKM vs. EPDM compatibility?
Request a quote or speak with one of our engineers T: +44 1509 218149
Request a quote or contact us
We offer.
- Same-day shipping on stocked O-rings
- Kits and bulk supply options
Whether you need O-rings for medical devices, chemical processing, or subsea applications, Rhondama delivers the right rubber sealing solution, fast.
