Nitrile is the most widely used elastomer in the seal industry. The popularity of nitrile is due to its excellent resistance to petroleum products. It has good physical properties and is superior to most rubbers in regards to compression set, tear and abrasion resistance. It offers high resistance to mineral oil based hydraulic fluids, silicone greases, petroleum-based oils, water and alcohols.
The major limiting properties of nitrile are its poor ozone and weather resistance and moderate heat resistance, but in many applications these are not limiting factors.

-22 °F
-30 °C

212 °F
100 °C

>excellent compression set
>good tear resistance
>good abrasion resistance
>good petroleum-based oils resistance
>good mineral oil based hydraulic fluids resistance
>good solvent, water and alcohols resistance

Application Disadvantages

HYDROGENATED NITRILE (HNBR)

HNBR is achieved by hydrogenated NBR. Greatly improved wear and extrusion resistance over standard NBR. Good chemical compatibility and it is excellent heat and oil resistant including exposure to such oil additives as detergents, anti-oxidants and anti-wear agents. It also shows a up to five times higher resistance to sour gas and ozone resistance. Has an extended high temperature range.

low

high

-22 °F
-30 °C

300 °F
149 °C

> excellent heat and oil resistance
>improved fuel and ozone resistance
(approximately 5X over Nitrile)
>excellent abrasion, compression set, tensiles, and tear properties
>exhibit better wear resistance than standard nitrile

Application Disadvantages

Seal and gasket application requiring additional resistance to chemicals and slightly higher temperatures than can be handled with NBR. O-Rings, washers, rod and piston seals, back-up rings, gaskets.

increased cold flow with hydrogenation
decreased elasticity at low temperatures with
Hydrogenation over standard nitrile
Not use for exposure to ketone, esters, aromatic fluids

FLUOROCARBON (FKM，FKM)

An excellent elastomer for use in high temperature applications. Also exhibits excellent chemical resistance, commonly referred as FKM or FKM. Fluorocarbon exhibits resistance to a broader range of chemicals combined with very good high temperature properties more so than any of the other elastomers. It is the closest available approach to a universal elastomer for sealing in the use of o-rings and other custom seals over other types of elastomers.
Fluorocarbons are highly resistant to swelling when exposed to gasoline as well as resistant to degradation due to expose to UV light and ozone.
In addition to standard FKM materials, a number of special materials are available with differing monomer compositions and fluorine content (65% to 71%) for improved low temperature, high temperature, or chemical resistance performance.
Fluorocarbons exhibit low gas permeability making them well suited for hard vacuum service and many formulations are self-extinguishing. FKM materials are not generally recommended for exposure to hot water, steam, polar solvents, low molecular weight esters and ethers, glycol based brake fluids, or hot hydrofluoric or chlorosulfonic acids.

low

high

-4 °F
-20 °C

392 °F
200 °C

>excellent chemical resistance
>excellent heat resistance
>good mechanical properties
>good compression set resistance
>Resistance to wide range of oils and solvents; specially all aliphatic, aromatic and halogenated hydrocarbons, acids, animal and vegetable oils

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
Automotive fuel handling
Aircraft engine seals
High temperature applications requiring good compression set performance
Tough sealing applications requiring extreme chemical resistance
General industrial seals and gaskets

poor low temperature flexibility
poor resistance to hot water and steam
not recommended for exposure to hot water, steam, polar solvents, low molecular weight esters and ethers, glycol based brake fluids, or hot hydrofluoric or chlorosulfonic acids.

ETHYLENE-PROPYLENE (EPDM)

Ethylene-propylene compounds are used frequently to seal in brake systems, and for sealing hot water and steam.  Ethylene propylene compounds have good resistance to mild acids, detergents, alkalis, silicone oils and greases, ketones, and alcohols. They are not recommended for applications with petroleum oils, mineral oil, di-ester lubricants, or fuel exposure.
Ethylene Propylene has gained wide seal industry acceptance for its excellent ozone and chemical resistance properties and is compatible with many polar fluids that adversely affect other elastomers.
EPDM compounds are typically developed with a sulfur or peroxide cure system. Peroxide-cured compounds are suitable for higher temperature exposure and typically have improved compression set performance.

low

high

-40 °F
-40 °C

302 °F
150 °C

>exceptionally good weather aging and ozone >resistance
>excellent water and chemical resistance
>excellent resistance to gas permeability and >aging due to exposure to steam
>good in ketones and Alcohols
>good heat resistance
>good low temperature flexibility

Application Disadvantages

standard and special sealing applications as hydraulic or rotary seal, O-rings, flange seals and gaskets
Water system seals, faucets, etc.
Brake systems
Ozone exposure applications
Automotive cooling systems
General Industrial Use

poor petroleum oil and solvent resistance
not recommended for food applications
not recommended for exposure to aromatic hydrocarbons

POLYURETHANE (AU) (EU)

Millable polyurethane exhibits excellent abrasion resistance and tensile strength as compared to other elastomers providing superior performance in hydraulic applications with high pressures, abrasive contamination and shock loads.
Its outstanding features are high resistance to abrasion, low compression set, high rigidity and high tear strength.
Polyurethane is used in industrial hydraulic systems (lip seals, chevron packings, wipers, rod seals, piston seals, O-rings and special seals), where improved performance and service life is important. It is resistant to petroleum oils, hydrocarbon fuels, ozone and weathering is good.

low

high

-22 °F
-30 °C

230 °F
110 °C

> excellent abrasion resistance
>excellent tensile strength and high rigidity
>low compression set
>good resistance to petroleum oils and hydrocarbon fuels
>good weather and ozone resistance

Application Disadvantages

Static and dynamic seals (standard and special), wiper, O-rings, back-up rings, flange seals, rotary seals:
seals for high hydraulic pressure
highly stressed parts subject to wear

poor resistance to water
poor high temperature capabilities

SILICONE (VMQ)

Silicone is a semi-organic elastomer with outstanding resistance to extremes of temperature with corresponding resistance to compression set and retention of flexibility. Silicone elastomers also have excellent weathering, ozone and aging properties.
Silicone rubbers have poor mechanical properties and abrasion resistance and are therefore mainly used for static sealing applications and are not recommended for dynamic applications. Silicones are highly permeable to gases, and are generally not recommended for exposure to ketones, concentrated acids, or steam.

low

high

-78 °F
-60 °C

392 °F
200 °C

> excellent extreme temperature properties
>excellent compression set resistance and good resilience
>moderate solvent resistance
>highly resistance to oxidation and ozone attack
very clean, low odor and taste

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
seals (static) for extreme temperature applications
food applications
medical devices
FDA applications

typically not good for dynamic seals due to friction properties and poor abrasion resistance
not recommended for most concentrated solvents, oils, concentrated acids and dilute sodium hydroxide

FLUOROSILICONE (FVMQ)

Fluorosilicone rubber which combines the good high and low temperature stability of Silicone with the fuel oil and solvent resistance of Fluorocarbons. It is most often used in aerospace applications for systems requiring fuel and/or diester-based lubricant resistance up to a dry heat limit of 400° F. Its features good compression set and resilience properties. It is suitable for exposure to air, ozone, chlorinated and aromatic hydrocarbons.

Fluorosilicone is designed for static sealing use. Because of its limited physical strength, poor abrasion resistance and high friction characteristics. Fluorosilicone is not recommended for dynamic sealing applications.  It is also not recommended for exposure to brake fluides, hydrazine, or ketones

low

high

-78 °F
-60 °C

347 °F
175 °C

>excellent extreme temperature properties
>excellent compression set resistance and good >resilience
>good fuel oil resistance
>very clean, low odor and taste

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
seals (static) for extreme temperature applications
aircraft fuel systems

typically not good for dynamic seals due to friction properties and poor abrasion resistance
not recommended for exposure to brake fluides, hydrazine, or ketones

NATURAL RUBBER (NR)

Natural rubber is a product coagulated from the latex of the rubber tree, hevea brasiliensis. Natural rubber features low compression set, high tensile strength, resilience, abrasion and tear resistance, good friction characteristics, excellent bonding capabilities to metal substrate, and good vibration dampening characteristics

low

high

-60 °F
-51 °C

220 °F
104 °C

> excellence compression set
>good resilience and abrasion
>good surface friction properties
>high tear strength
>low crack growth
>good low temperature properties

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
rubber to metal bonded vibration isolators and mounts
automotive diaphragms
FDA applications for food and beverage seals

poor resistance to attack by petroleum oils
poor ozone, UV resistance

NEOPRENE / CHLOROPRENE (CR)

Neoprene homopolymer of chlorobutadiene and is unusual in that it is moderately resistant to both petroleum oils and weather (ozone, UV, oxygen). This qualifies neoprene uniquely for certain sealing applications where many other materials would not be satisfactory. Neoprene is classified as a general purpose elastomer which has relatively low compression set, good resilience and abrasion, and is flex cracking resistant.
Neoprene has excellent adhesion qualities to metals for rubber to metal bonding applications.
It is used extensively for sealing refrigeration fluids due to its excellence resistance to Freon and ammonia.

low

high

-40 °F
-40 °C

250 °F
121 °C

>high resilience with low compression set
>moderate resistance to petroleum oils
>good resistance to ozone, UV, oxygen
>excellence resistance to Freon and ammonia

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
refrigeration industry applications
general purpose seals, hose and wire

moderate water resistance
not effective in solvents environments

STYRENE BUTADIENE (SBR)

Styrene-Butadiene (SBR) is a copolymer of styrene and butadiene.
SBR compounds have properties similar to those of natural rubber. SBRs primary custom molded application is the use in hydraulic brakes system seals and diaphragms, with the major of the industry usage coming from the Tire Industry.
SBR features excellent resistance to brake fluids, and good water resistance.

low

high

-50 °F
-46 °C

212 °F
100 °C

>good resistance to brake fluids
>good resistance to water
>low cost non-oil resistance material

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
hydraulic brake systems seals and diaphragms
plumbing applications

>poor weather resistance
>poor petroleum oil and solvent resistance

POLYACRYLATE (ACM)

Polyacrylates are copolymers of ethyl and acrylates which exhibit excellent resistance to petroleum fuels and oils and can retain their properties when sealing petroleum oils at continuous high temperatures up to 347 °F. These properties make polyacrylates suitable for use in automotive automatic transmissions, steering systems, and other applications where petroleum and high temperature resistance are required.
Polyacrylates also exhibit resistance to cracking when exposed to ozone and sunlight.
Polyacrylates are not recommended for applications where the elastomer will be exposed to brake fluids, chlorinated hydrocarbons, alcohol, or glycols

low

high

-60 °F
-51 °C

300 °F
149 °C

>petroleum fuel and oil resistance
>resists flex cracking
>good ozone resistance
>good heat resistance

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
Automotive transmissions.
Automotive steering systems

poor compression set performance relative to NBR
lesser water resistance and low temperature performance than some other elastomers

ETHYLENE ACRYLIC (AEM)

Ethylene-acrylic (Vamac ) is a terpolymer of ethylene, methyl acrylate, and an acid-containing monomer as a cure site. It exhibits properties similar to those of Polyacrylate, but with extended low temperature range and with enhanced mechanical properties.
Ethylene-acrylic offers a high degree of oil, ozone, UV and weather resistance.

low

high

-40 °F
-40 °C

300 °F
149 °C

>excellent vibration dampening
>excellent heat aging characteristics
>good dynamic property retention over a wide temperature range
>resistance to transmission fluids, water, glycol mixtures, and alkalies

Application Disadvantages

O-rings, rubber seals and custom molded rubber components for:
Automotive sealing applications.
Automotive transmissions
Power steering seals

not recommended for exposure to fuel, brake fluid, aromatic hydrocarbons or phosphate esters.

Virgin PTFE (PTFE Virgin)

PTFE Virginis a tough high temperature material offering the widest range of applications. Resistant to almost all chemicals (only solid alkalies can attack PTFE), its very low coefficient of friction and high impact resistance make it suitable for wide chemical exposure situations, with emphasis on temperature extremes.
Virgin PTFE is used for spring-energized seals, V-packings, 0-rings, back-up rings, wiper, rod and piston profiles, valve seats & seals and machined components used in the chemical industry, food processing equipment and other high temperature and low friction sealing applications.
Virgin PTFE has the tendency to cold flow over time under load or pressure. Filled PTFE is therefore required in critical sealing situations.

low

high

-328 °F
-200 °C

500 °F
260 °C

>excellent low friction
>excellent extreme temperature properties
>excellent chemical resistance
>excellent dielectric properties

O-rings, Spring-Energized Seals, V-packings, back-up rings, wiper, valve seats, rod & piston profiles, shaft seals, lip seals, Gaskets, guiding/bearing elements, machined components.
Petrochemical and chemical processing
Electrical applications
Semi-Conductor Industry
Food, Beverage and Pharmaceutical industries
Laboratory applications

PTFE Filled (PTFE Filled)

PTFE Filled has improved mechanical properties over virgin PTFE. The influence of filler materials results in an increase in mechanical strength, increase in hardness, reduction of wear and/or friction, improvement in the flow strength and increase in thermal shape stability.  The most important fillers: glass, carbon, graphite, bronze, nickel, MOS2, mica, and high performance polymers and minerals.
Glass filled PTFE, significantly improved wear resistance and heat transfer due to glass filler. Excellent for dynamic applications and for higher pressures.
Bronze filled PTFE, improved wear resistance, hardness and compressive strength. The electrical properties and chemical resistance are reduced. Excellent for dynamic applications and pressures to 6000 psi. Graphite filled PTFE, Self lubricating. Significant increased thermal conductivity, reduced level of creep. Nickel filled PTFE, Similar to PTFE / Glass or PTFE / Bronze but with superior chemical, wear and extrusion resistance. Excellent for dynamic applications and pressures to 6000 psi.

low

high

-328 °F
-200 °C

500 °F
260 °C

>improved wear resistance
>improved heat transfer
>increase in mechanical strength
>improved extrusion resistance
>improved low friction
>increase in thermal conductivity

Glass filled PTFE, excellent for dynamic applications and wear parts requiring low friction and good wear resistance and high pressure resistance.
Bronze filled PTFE, used in dynamic sealing applications, Wear parts in hydraulic cylinders requiring load bearing along with low friction guiding parts, sealing rings
Graphite filled PTFE, high speed applications
Nickel filled PTFE, excellent for dynamic applications and pressures to 6000 psi.

ACETAL (Delrin, POM)

Acetal has gained widespread recognition for its reliability of performance. It has high mechanical strength, rigidity, dimensional stability, high impact strength and good abrasion.
Acetal exhibits a high thermal stability and a high resistance to chemicals (high resistance to hydrolysis)

low

high

-58 °F
-50 °C

230 °F
110 °C

>no microporosity
>high strength and rigidity
>high thermal stability
>good electrical insulation properties
>very good sliding properties
>high resistance to solvents
>very high resistance to stress cracks

Application Disadvantages

Wear rings, back up rings, bushings and bearings, gear wheels, parts of pumps, screws, ornamental mountings and fittings, parts for the textile industry

not resistance to high concentrated acids
difficult to glue and paint

NYLON (PA6, PA6.6)

Nylon has very good physical properties and is one of the most widely used engineering plastics in the industry today. PA shows a high thermostability, also high stiffness, hardness and toughness are some of its main characteristics. Due to the fact, that the good mechanical properties will be achieved only after conditioning. This material must be conditioned again after an annealing. In addition, this conditioning occurs with a longer storage in air automatically.

low

high

-58 °F
-50 °C

230 °F
110 °C

>high strength and stiffness
>high impact and notch impact strength
>high heat deflection temperature
>good at dampening
>good abrasion resistance
>low coefficient of friction
>good chemical stability against organic solvents and fuels
>food safe

Application Disadvantages

Wear rings, back-up rings, bearings parts (good sliding properties), gear wheels, pump parts, parts in the automotive manufacturing (e.g. lock parts, chain wheels, housings, carburetor parts, etc), sliding parts, castors( reduction of the noise level), fittings, etc…

dimension stability, electrical and mechanical properties may become affected by absorbing moisture or water

PEEK

Polyether etherketone can be used at very high temperatures (+260°C) and it shows an extraordinary mechanical strength, toughness, hardness, flexural strength, trosional strength. PEEK exhibits excellent chemical resistance, very good dielectric properties up to +260°C and a very good resistance to all kinds of radiation. Importantly it is self-extinguishing according to UL 94.

low

high

-40 °F
-40 °C

500 °F
260 °C

>excellent mechanical strength
>excellent rigidity
>excellent thermal stability
>excellent dimensional stability
>excellent radiation resistance
>excellent hydrolysis resistance

Application Disadvantages

Bearing shells, piston rings, valve seats, gears, seals, aviation, pump vanes, plug connectors, wafer carriers.

notched impact strength relatively low
low resistance to acetone

PSU

Polysulfone show great thermal stability (from -100 to +160°C). PSU possess a high mechanical strength, very good dielectric properties and hydrolysis resistance. High radiation resistance and self-extinguishing. PSU has a low notch impact strength.

low

high

-148 °F
-100 °C

320 °F
160 °C

>high strength and rigidity
>high impact strength (also at low temperature)
very good dimensional stability
>high chemical resistance
>high resistance to all kinds of radiation
>self-extinguishing
>low smoke emission
>repeated sterilization

Parts for microwave ovens, blow-dryers, food industry, pump wheels, insulators, medical industry, etc…

PPSU

Polyphenylensulfone is an amorphous material, with improved impact, chemical resistance and hydrolysis resistance compared to PSU. The ususal operating temperature is with approx. 180°C. The extremely high notched impact strength remains also after a heat aging.

low

high

-58 °F
-50 °C

356 °F
180 °C

>high strength and rigidity
>very high impact strength (also at low temperature)
>very good dimensional stability
>very high chemical resistance
>high resistance to all kinds of radiation
>self-extinguishing
>repeated sterilization

As with PSU but with higher chemical resistance

PEI

Polyetherimide has a high mechanical strength in coordination with a good chemical and heat resistance (up to +170°C). good dimensional stability and creep resistance. Its under the thermoplastics singular torque strength permits the economical substitution of machining fabricated small parts from steel.

low

high

338 °F
170 °C

>very high strength and rigidity
>high torque strength and hardness
>high thermostability
>high weatherability
>high radiation resistance
>self-extinguishing

Parts for electrical engineering, food industry and in the aircraft construction, etc….

PET

Polyethylence terephthalate shows high tensile and mechanical strength, hardness and toughness, low friction and a high dimensional stability. PET may be used at temperatures ranging from -40°C to +110°C.

low

high

-40 °F
-40 °C

230 °F
110 °C

Bearings
Pumps
parts for housings
tank lids
cogwheels
insulators

>high mechanical resistance and tensile strength
>high surface strength
>high dimensional stability
>high toughness
>low coefficient of friction
>low wear and tear
>high chemical resistance
>easy to varnish and polish
>good electrical insulating properties

limited dielectric properties
sensitive to hydrolysis

PVDF (Kynar)

PVDF shows a higher tensile strength, pressure resistance and dimensional stability than the related PTFE, but friction and insulation properties are lower. PVDF has a high mechanical strength and toughness at lower temperature and its self-extinguishing. The temperature ranges from -30°C to +150°C

low

high

-22 °F
-30 °C

302 °F
150 °C

Pumps, rotation disks, valves, fittings, glide tracks, cogwheels, chemical processing.

>high mechanical strength and tensile strength
>high chemical resistance
>low water absorption
>good friction and wear and tear values
>self-extinguishing
>high UV-resistance

toxic fumes when burned
can not be solvent cemented

E-CTFE (Halar)

E-CTFE exhibits an extraordinary impact strength at temperatures ranging from -76°C to +150°C. A great part of the product properties attributes to the very smooth surface and differentiates Halar from other fluoropolymers. Due to the fact that E-CTFE is very pure, this material is being used to process chemicals and ultrapure water for the semiconductor industry. Also the permeation resistance to oxygen, carbon dioxide, chlorine gas and hydrochlorid acid is 10 to 100 times better than PTFE.

low

high

-105 °F
-76 °C

302 °F
150 °C

Parts which come in contact with aggressive materials (e.g. machine-making industry). Lining of tanks, pumps, flanges, fitting, parts in centrifuges and control engineering industry etc…

>extremely high impact strength(up to -40°C)
>good insulation properties
>very good weather resistance
>high resistance to radiation
>very high chemical resistance
>self-extinguishing
>very good sliding properties
>food safe

high density
limited protection against stress cracking at temperatures > 140°C

PPE

PPE belongs to the group of the amorphous materials and can be used in temperatures ranging from -50 to +105°C.
PPE exhibits a high impact strength and a very high dimensional stability. The electrical properties will not be influenced by the surrounding frequencies and therefore can be used in a lot of applications in electrical engineering.

low

high

-58 °F
-50 °C

221 °F
105 °C

parts for electrical engineering and household utensils, shafts, gear wheels, etc….

>high dimensional stability
>low tendency to creep
>high thermostability and impact strength
>good electrical properties over a far frequency range
>high resistance to hydrolysis
>self-extinguishing

PE-UHMW

PE-UHMW offer resistance to almost all acids and bases, detergents and hot water. PE-UHMW has good insulation properties and is easy to weld. The operating temperature of PE-UHMW is from -150°C and +90°C.

low

high

-238 °F
-150 °C

194 °F
90 °C

Sewage industry
pumps and valves
seals
medical industry

>very low friction
>low density
>high toughness(also at low temperature)
>high elongation
>very good electrical and dielectric properties
>very low water absorption
>low steam permeability
>high chemical resistance
>good protection against stress cracking
>food safe

Application Disadvantages

high density
limited protection against stress cracking at temperatures > 140°C

PVC is rated self-extinguishing, has an exceptional chemical resistance and is easy to machine. PVC shows high mechanical strengths, tensile strength and can be used in application ranging in temperature from -15°C to +60°C. it can also be easily solvent cemented and welded.

low

high

5°F
-15 °C

140F
60C

Pumps and valves, seals, pipe systems, bearings, brush industry,
Lamp housing, parts for the dental industry, chemical tanks

>high mechanical strength, tensile strength and hardness
>good insulation properties
>high chemical resistance
>self-extinguishing
>low water absorption
>easy to varnish and glue

Application Disadvantages

low impact strength
limited weather resistance