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- EPDM and NBR Where Each One Belongs and Where It Fails
These two compounds cover an enormous share of industrial sealing between them, and they fail in each other's territory. Getting the boundary right removes most avoidable seal problems.
EPDM Belongs in Water Weather and Heat
EPDM offers good heat, ozone and weather resistance, which is why it is used so widely in automotive, electrical and electronic products, wires and cables, high voltage and ultra high voltage insulation, sports equipment, daily necessities and mechanised industrial equipment. Heating systems, water systems, automotive brake circuits and refrigeration units are its natural home, and food grade EPDM extends it into food processing.
EPDM Seals and EPDM O-Rings →
EPDM Fails in Mineral Oil
The single most common EPDM mistake is putting it in contact with mineral oil or fuel. It is not marginal there, it is wrong, and the seal swells. If there is any hydrocarbon in the circuit, EPDM is off the list regardless of how well it suits the temperature.
NBR Belongs Where There Is Oil
NBR is chosen for its resistance to oils, fuels and other hydrocarbons, which makes it the workhorse for automotive, aerospace, wire and cable and home appliance applications. Where a circuit handles oil or fuel at moderate temperature, NBR gives the best balance of cost against performance in our range.
NBR O-Rings →
NBR Fails in Weather and Ozone Exposure
Outdoors, in ozone rich environments or under prolonged weather exposure, NBR is the wrong choice and EPDM is the right one. The two failure modes are mirror images, which is why a plant that standardises on one compound for everything eventually sees failures in both directions.
What to Do When You Need Both
Most real machines contain both an oil circuit and a water or weather exposed circuit, which means a mixed seal schedule is normal rather than a sign of poor standardisation. Consolidating that mixed schedule with one supplier who holds both compounds is the practical answer, and it is why buyers bring twelve compound schedules to us on a single purchase order.
Rubber Seals →
Products Mentioned in This Guide
EPDM Seals and EPDM O-Rings
EPDM has good weather resistance and unusual versatility, which is why it appears across automotive, electrical and electronic products, daily necessities, sports equipment and mechanised industrial equipment, as well as in wires, cables and high voltage and ultra high voltage insulation materials.
NBR O-Rings
NBR is the working compound for anything that meets oil or fuel at moderate temperature.
O-Rings
An O-ring is the cheapest part in most assemblies and the most common cause of a warranty return.
Industrial Rubber Rollers
In printing and converting the roller covering is a process variable rather than a spare part.
Quick Answers
Yes, EPDM is used in automotive brake systems. It is mineral oil and fuel that rule it out.
Not where weather and ozone exposure are significant. EPDM is the better choice there.
Tell us the requirement and the standard you need to meet, and we will confirm what we can supply before you commit.
Put This Into a Quotation
Send the size, the medium and the quantity, and we will apply exactly the reasoning in this guide to your part.
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