Metric O-Rings function primarily as gaskets that seal connections between structures like pipes and tubes or within pistons and cylinders. They’re typically made of pliable materials like rubber or high-quality PTFE. When pressed between two mating surfaces, they effectively block the passage of liquids or gases.
Whether a PTFE or rubber seal, metric o-rings come in two main forms: static or dynamic. A static seal is where the ring remains stationary and is used simply for containing pressure or maintaining a vacuum. Dynamic seals can be either reciprocating (for use in pistons and cylinders) or rotating (for applications in which a shaft rotates inside a housing).
Manufactured From Durable Materials
Short for polytetrafluoroethylene, PTFE can stand up to a wide temperature range and offers electrical and thermal insulation.Learn more >
Silicone offers high dielectric stability in addition to excellent heat, ozone and corona resistance. It also possesses the best flexible property at low temperatures and is resistant to many oils, chemicals, and solvents.Learn more >
Viton is a high performance rubber with excellent resistance to high temperatures, ozone, oxygen, mineral oil, fuels, hydraulic fluids, aromatics and many organic solvents and chemicals.Learn more >
Buna (a.k.a. NBR) is a rubber that is highly wear resistant, has good mechanical properties when compared with other elastomers and exhibits a resistance to oil and fuel.Learn more >
EPDM is a rubber with excellent resistance to ozone, sunlight and weathering - It has very good flexibility at low temperatures and good chemical resistance and electrical insulation properties. Short for ethylene propylene diene monomer.Learn more >
Metric O-Ring Kits
When parts, part numbers and/or seal dimensions are missing, these kits are a life saver.Learn more >
As a trusted PTFE and silicone o-ring manufacturer, we offer a multitude of materials and durometers (ranging from 25 to 90 durometers on the Shore Hardness Scale) to fulfill practically any need. In addition to standard materials, we offer a variety of specialty grade materials such as USP medical-grade Class VI PTFE, NSF, FDA, and 3A sanitary grades. Whether you need high flexibility at low temperatures, resistance to heat, high dialectric stability — or anything in-between — these materials will get the job done.
Static & Dynamic O-Ring Sizes & Groove Dimensions
In the o-ring size diagram above, the measurement “b” (which is the width of the groove) must be larger than the deformed o-ring itself. Depending on application, the groove may be open on one side. However, the pressure applied to the medium to be sealed must have full access to the o-ring. The surfaces of the groove and the opposing surfaces should have (more or less) rounded processing traces to permit peak-to-valley heights of 44 to 25 μm.
Static Seal Groove Dimensions
In case of applying back-up rings, the width of groove “b” is increased by the width of the back-up ring resp. in case of support on either side by the double width of the back-up ring.
Dynamic Seal Groove Dimensions by Application