The right rubber depends on what the part touches. Use EPDM outdoors, with water or steam. Use nitrile with oils and fuels, and neoprene for moderate oil and weather. Choose silicone for extreme temperatures or food contact, and Viton (FKM) for high heat with aggressive chemicals or fuels. Walker Rubber extrudes and moulds all five in-house in Norwich.
Not sure which compound? Send us your application details and we’ll recommend one.
Which rubber should I choose? The quick answer
If your part is exposed to… | Choose | Avoid |
Sunlight, ozone, rain, outdoor weather | EPDM | Nitrile, natural rubber |
Mineral oils, diesel, grease, hydraulic fluid | Nitrile (NBR) | EPDM, silicone |
Some oil plus weather (marine, general industrial) | Neoprene (CR) | Natural rubber |
Temperatures above 150°C or below −40°C | Silicone | Nitrile, neoprene |
Food or drink contact | Silicone or food-grade EPDM / nitrile | Standard black compounds |
Fuels, acids or solvents at high temperature | Viton (FKM) | EPDM, silicone, neoprene |
Abrasion or impact | Natural rubber or polyurethane | Silicone |
How do the five rubbers compare?
Property | EPDM | Neoprene | Nitrile | Silicone | Viton (FKM) |
Typical service temperature | −45 to +125°C | −35 to +100°C | −25 to +100°C | −60 to +200°C | −20 to +200°C |
Weather, UV and ozone | Excellent | Good | Poor | Excellent | Excellent |
Mineral oil and fuel | Poor | Fair | Excellent | Poor | Excellent |
Water and steam | Excellent | Good | Good | Good | Fair |
Abrasion and tear | Good | Good | Good | Poor | Fair |
Flame resistance | Poor (FR grades exist) | Good, self-extinguishing | Poor | Good | Excellent |
Food-grade options | Yes | Limited | Yes | Yes, widely used | Yes |
Relative cost | £ | ££ | £ | £££ | ££££ |
Disclaimer: Ratings are general guidance. Exact performance depends on the compound and hardness, so ask us for the datasheet of the grade you’re quoted.
What is EPDM rubber best for?
EPDM (ethylene propylene diene monomer) is a synthetic rubber for outdoor and water-facing seals. It resists UV, ozone and weathering for decades, and peroxide-cured grades handle steam. EPDM swells badly in oil and fuel.
- Typical extrusions: window and glazing seals, door seals, container door seals, gate seals.
- Typical mouldings: grommets, outdoor bellows, water-system seals (WRAS grades available).
What is neoprene rubber best for?
Neoprene (polychloroprene, CR) is a general-purpose rubber with moderate oil resistance and good weathering. It is self-extinguishing, which makes it a common choice where fire behaviour matters. It is weaker than EPDM in long-term UV, and weaker than nitrile in oil.
- Typical extrusions: marine and industrial seals, cable protection, edge trims.
- Typical mouldings: bushes, anti-vibration pads, dust covers.
What is nitrile rubber (NBR) best for?
Nitrile (NBR) is the standard rubber for oils, fuels and greases. The more acrylonitrile in the compound, the better its oil resistance and the worse its low-temperature flexibility. It cracks in ozone and sunlight unless it is protected.
- Typical extrusions: machinery and hydraulic seals, oil-contact cord and tube.
- Typical mouldings: grommets and seals near engines, gearboxes and hydraulics.
What is silicone best for?
Silicone (VMQ) is the widest-temperature general rubber, and it’s the default for food, drink and pharmaceutical contact. It is clean, odourless and available in translucent and coloured grades. Silicone has low tear and abrasion strength, so it suits static seals better than wearing parts.
- Typical extrusions: oven and autoclave door seals, food-grade cord and tube, silicone sponge seals.
- Typical mouldings: food-line seals, high-temperature gaskets.
What is Viton rubber (FKM) best for?
Viton is a brand name for FKM fluorocarbon rubber, the premium choice for heat combined with fuels, oils and many acids. It costs several times more than nitrile, so specify it only when the chemistry or temperature demands it. Standard grades stiffen below about −15°C.
- Typical extrusions: chemical-plant seals, Viton cord for fuel systems.
- Typical mouldings: seals for pumps, valves and fuel handling.
EPDM vs neoprene: which is better outdoors?
EPDM is better for long-term outdoor exposure, because it holds its properties in UV and ozone longer and costs less. Neoprene is the better pick when the seal will also see oil splash or needs better fire behaviour.
EPDM vs silicone: when is silicone worth the extra cost?
Silicone is worth it above about 125–150°C, below −40°C, or where food contact needs FDA or EC 1935/2004 compliance. For general outdoor sealing between those limits, EPDM is tougher and cheaper.
Nitrile vs Viton: which for oil and fuel?
Nitrile handles most oils and fuels up to about 100°C at a fraction of the cost. Choose Viton when temperatures run higher, when the fluid is a biofuel, aromatic fuel or acid, or when a nitrile part is swelling or hardening early.
Does the material change how the part is made?
Yes, but all five can be both extruded and moulded. Silicone and Viton need cleaner handling and different cure systems. Material choice can also change tooling: shrinkage varies by compound, so a die or mould is cut for a specific material. Changing compound later may mean new tooling.
How does Walker Rubber compare?
| Walker Rubber | Typical high-volume or overseas supplier |
Materials in-house | EPDM, neoprene, nitrile, natural rubber held on site; silicone and Viton sourced to order. | Often one or two standard compounds |
Minimum order (extrusions) | No MOQ on standard compounds once tooling exists | Often thousands of metres |
Samples | Profile samples in under 72 hours after the die is made | Weeks, plus shipping |
Material advice | Technical team in Norwich, UK | Sales contact, often overseas |
Frequently asked questions
Which rubber is best for outdoor seals?
EPDM. It has excellent resistance to UV, ozone and weathering, and it outlasts nitrile and natural rubber outdoors.
Which rubber is oil resistant?
Nitrile is the standard oil-resistant rubber. Viton handles oil at higher temperatures, and neoprene gives moderate oil resistance.
Is Viton better than silicone?
For fuels, oils and chemicals, yes. Silicone is better at very low temperatures, for food contact and on cost.
What rubber is food safe?
Silicone is the most common food-safe rubber. Food-grade EPDM, nitrile and Viton compounds are also available with FDA or EC 1935/2004 compliance.
What is the highest-temperature rubber?
Silicone and Viton both run continuously at around 200°C, and some grades go higher.
Is neoprene the same as EPDM?
No. Neoprene (polychloroprene) has some oil resistance and self-extinguishes; EPDM has better weathering and costs less but swells in oil.
Can you extrude and mould the same material?
Yes. Walker Rubber extrudes and moulds all five materials, so a moulded corner or end cap can match the compound of the extruded seal.
How do I choose if I’m not sure?
Send us the temperature range, the fluids the part touches, whether it’s indoors or outdoors, and any approvals needed. We’ll recommend a compound and sample it.
Find the right compound for your part
Send us your drawing or application details and get profile samples in under 72 hours.