Can EPDM be used for oil sealing?

No. EPDM has poor resistance to mineral oil, hydraulic oil and hydrocarbon fuels. It will swell, soften and lose sealing performance quickly.

Is silicone rubber good for dynamic shaft seals?

Generally not recommended. Silicone has low tear strength and poor abrasion resistance. It works best for static sealing applications.

What is the difference between high ACN and low ACN NBR?

Higher ACN content delivers better oil and fuel resistance, while lower ACN improves low-temperature flexibility.

Which rubber lasts the longest outdoors under sunlight?

EPDM and silicone both have excellent UV and ozone resistance. NBR will crack rapidly under outdoor exposure without special protection.

Can NBR resist hot steam?

Only fair resistance. For steam and hot water sealing, EPDM is the better option.

Which material is food safe?

Silicone has the widest selection of FDA and food-contact approved grades. EPDM and NBR food-grade options are limited.

What if my application needs both oil resistance and ozone resistance?

Standard EPDM, silicone and NBR cannot meet this requirement. You need to consider HNBR or FKM (Viton).

EPDM vs Silicone vs NBR: Which Rubber Material Is Right for Your Sealing Application?

EPDM, Silicone and NBR O-rings comparison

If you’ve ever had a seal swell, crack or leak after short service life, you know how tricky rubber selection can be. For most standard sealing jobs, three elastomers come up time and time again: EPDM, Silicone (VMQ), and NBR (Nitrile / Buna-N).

Instead of long blocks of text, I’ve structured this guide mostly in tables so you can quickly scan specs, strengths, weaknesses and use cases.

1. Basic Material Overview Table

Rubber damping pads and vibration isolation washers

Item	EPDM	Silicone (VMQ)	NBR (Nitrile Butadiene Rubber / Buna-N)
Full chemical name	Ethylene Propylene Diene Monomer	Polysiloxane (VMQ)	Nitrile Butadiene Rubber
Polymer backbone	Saturated carbon chain (ethylene + propylene + diene)	Inorganic silicon‑oxygen backbone	Unsaturated carbon chain (butadiene + acrylonitrile copolymer)
Key structural feature	Almost no reactive double bonds	Si-O bonds, highly thermally stable	Acrylonitrile (ACN) groups provide oil resistance; performance changes with ACN content
Core positioning	Weather & water-resistant general-purpose rubber	Extreme temperature, food & medical static seal rubber	Low-cost oil-resistant workhorse rubber
Typical colour	Black (most common); custom coloured	Translucent, white, red, black	Black (standard)

2. Temperature & Environmental Resistance Table

NBR rubber rotary shaft oil seal for hydraulic applications

Performance Metric	EPDM	Silicone (VMQ)	NBR
Continuous operating temperature	-40°C ~ 125°C; peroxide-cured grade up to 150°C	-60°C ~ 200°C	-30°C ~ 120°C
Short peak temperature	160°C	230°C	135°C
UV / ozone resistance	Excellent	Excellent	Poor
Outdoor weather aging	Excellent	Excellent	Poor; cracks fast under sun/ozone without special additives
Hot water & steam	Very good	Moderate	Fair
Mineral oil, hydraulic oil, grease	Poor – severe swelling	Poor – severe swelling	Excellent
Gasoline / diesel fuel	Poor	Poor	Good to excellent (depends on ACN %)
Dilute acids & alkalis	Very good	Good	Moderate
Polar solvents (ketones, esters)	Good	Poor	Poor

3. Mechanical & Physical Properties Table

Food grade silicone baking mold for kitchen and food processing

Property	EPDM	Silicone (VMQ)	NBR
Tensile strength	Good	Low	Very good
Tear resistance	Good	Low	Very good
Abrasion / wear resistance	Good	Poor	Excellent
Compression set	Good (peroxide cured best)	Moderate	Good
Dynamic sealing suitability	Moderate	Not recommended	Excellent
Static sealing suitability	Excellent	Excellent	Very good
Electrical insulation	Excellent	Excellent	Fair

4. Suitable & Unsuitable Applications Table

Category	EPDM	Silicone (VMQ)	NBR
✅ Best applications	Automotive weatherstrip, radiator/glycol seals, HVAC gaskets, outdoor electrical enclosures, solar gaskets, hot water/steam seals, roof sealing	Food & beverage gaskets, oven/appliance seals, medical components, cryogenic static seals, high-temperature air seals, vacuum static seals	Hydraulic O-rings, oil lip seals, engine/grease seals, fuel transfer gaskets, pump & valve dynamic seals, low-cost industrial OEM seals
❌ Avoid these scenarios	Any continuous contact with oil, fuel, hydrocarbon lubricants	High-friction moving seals, rotary shaft seals, oil circuits, heavy abrasion environments	Long-term outdoor exposure, ozone-rich environments, continuous hot steam, ketones & ester solvents
✅ Available special grades	Peroxide-cured, low compression set, black/coloured	FDA food grade, USP Class VI, low volatile, high-temperature	Low ACN (cold-resistant), high ACN (super oil-resistant)

5. Cost & Compliance Summary Table

Comparison	EPDM	Silicone (VMQ)	NBR
Relative raw material cost	Low	Medium to high	Low
General availability	Very widely stocked	Common, but more expensive	The most stocked O-ring material globally
Food contact certification	Limited options	Wide range of certified grades	Limited food-grade options
Medical grade	Rare	Standard offering	Rare

6. Quick Decision-Making Table (Cheat Sheet for Engineers)

Your working condition	First choice	Notes
Sealing oil, hydraulic fluid or grease	NBR	Best for dynamic oil seals
Exposed outdoors, sun, ozone, sealing water / glycol / steam	EPDM	Never use for oil
Static seal, extreme heat or cold, food/medical requirement, no oil	Silicone	Not for moving friction surfaces
Budget-sensitive oil sealing	NBR	Check if outdoor exposure exists
Long-term outdoor static sealing, no oil	EPDM	Cheaper than silicone

7. Frequently Asked Questions

Question	Answer
Can EPDM be used for oil sealing?	No. EPDM has poor resistance to mineral oil, hydraulic oil and hydrocarbon fuels. It will swell, soften and lose sealing performance quickly.
Is silicone rubber good for dynamic shaft seals?	Generally not recommended. Silicone has low tear strength and poor abrasion resistance. It works best for static sealing applications.
What is the difference between high ACN and low ACN NBR?	Higher ACN content delivers better oil and fuel resistance, while lower ACN improves low-temperature flexibility.
Which rubber lasts the longest outdoors under sunlight?	EPDM and silicone both have excellent UV and ozone resistance. NBR will crack rapidly under outdoor exposure without special protection.
Can NBR resist hot steam?	Only fair resistance. For steam and hot water sealing, EPDM is the better option.
Which material is food safe?	Silicone has the widest selection of FDA and food-contact approved grades. EPDM and NBR food-grade options are limited.
What if my application needs both oil resistance and ozone resistance?	Standard EPDM, silicone and NBR cannot meet this requirement. You need to consider HNBR or FKM (Viton).

Tables make comparison fast, but every sealing project has edge cases. If your working conditions combine high temperature + oil + ozone, these three standard rubbers may not be enough — you would need HNBR or FKM instead.

If you share your media, temperature, static/dynamic movement and hardness requirement, we can recommend the exact rubber grade for your gasket or O-ring.

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