Elastomeric Material Products

An elastomeric material is any material exhibiting elastic or rubber-like properties. Elastomeric materials are measured in material type, compound, and durometer (the material’s hardness). Since there are such a wide variety of elastomeric materials, the application is critical to understanding the job’s best material compound.

Elastomeric Material Comparison Data Sheet

Foam / Sponge

Foam and sponge are generally grouped and regarded as in the same elastomeric/plastic materials family because they exhibit the same cellular structure. Additionally, they are commonly listed under similar industry specifications (ASTM, MIL, UL, FMVSS, and others).

Foam is a lightweight, open-cell product that is typically used for insulation, filtration, and cushioning. These low density cellular materials allow air movement through the cell structure. In addition to traditional foam’s legacy applications, high-density foams have been developed for fluid sealing applications. In contrast, higher-density foam products will have a higher concentration of cells. Medium and low-density foams will have a lower concentration of cells.

The sponge is an expanded, rubber-based elastomeric material. The sponge can be processed in multiple material formulations (different compounds, densities, and open and closed cellular structures). The cells are not connected, which keeps the material from absorbing and retaining liquid. Compared to foams, sponges are considered to have superior mechanical properties.

Sponge and Foam are available in sheets, rolls, and molded or extruded shapes. As needed, they can be ordered with or without ‘skin’ and PSAs (pressure-sensitive adhesive).

COMMON BRANDS: Rogers, Monmouth, Armacel, K-Flex, Rubatex, Griswold
COMMON TRADE NAMES: Poron, Bisco, EnsoLite®



  • Filtration
  • Thermal Insulation
  • Cushioning
  • Padding
  • Gaskets
  • Weather Stripping
  • Sound Barrier

To learn more about foam and sponge elastomeric material from The Gund Company or request a quote for your application, Contact Us Today!


ASTM D1056-072A12A22A32A52A12A22A32A1
GRADE CONDITIONSoftSoft-MedMediumFirmSoftSoft-MedMedium—–
MIL-C-3133C MIL STD 6708SCE3 F2SCE7 F2SCE11 F2SCE20 F2RE3 F2RE7 F2RE11 F2RE3
UL94 HF1ListedListedListed—–—–—–—–—–
UL94 HBFListedListedListed—–—–—–—–—–
25% Compression Deflection [psi]2-55-99-1317-252-55-99-132-5
Density Approximate [pcf]6 +/-26 +/-29 +/-212 +/-26 +/-26 +/-29 +/-24 +/-1
Water Absorption Max. Weight %55555555
Temperature Range oF-40/+200-40/+200-40/+200-40/+150-70/+220-70/+220-70/+220-40/+200
Temperature High Intermittent oF250250250200250250250250
Ozone ResistanceExcellentExcellentExcellentFairExcellentExcellentExcellentExcellent
Tensile Strength [psi]75100100150757510040
Fuel B Max. % Weight Changen/an/an/an/an/an/an/an/a
Elongation Typical Properties %125125125125125125125175
Durometer Shore 00 [Approx.]40-5045-5555-6565-7540-5045-5555-6537-47
Shrinkage 7 Days @ 158o Max.5%5%5%5%5%5%5%5%
K Factor0.300.300.38—–0.30.300.38030
ASTM D1056-072C12C22A1/2A22A2/2A32C12C22B3 
MIL-R-6130 TYP + ASTM D6576II-AII-A—–—–11-B11-A/B11-A/B 
GRADE CONDITIONSoftSoft-Med—–—–SoftSoft-MedMedium 
MIL-C-3133C MIL STD 6708SCE3 F1SCE7 F1—–—–SCE3SCE7SCE11 
UL94 HF1PassPass—–—–ListedListedListed 
UL94 HBFPassPass—–—–PassPassPass 
25% Compression Deflection [psi]2-55-94-69-132-55-99-13 
Density Approximate [pcf]9 +/-29 +/-22 +/-53.0-4.03.0-5.05.5-7.57.0-9.5 
Water Absorption Max. Weight %551010755 
Temperature Range oF-40/+150-40/+150-110/+220-110/+220-40/+200-40/+200-40/+200 
Temperature High Intermittent oF200200240240225225225 
Ozone ResistanceFairFairExcellentExcellentFairFairFair 
Tensile Strength [psi]8090601005075100 
Fuel B Max. % Weight Change<250<250n/an/a<250<250<100 
Elongation Typical Properties %150150275310100100100 
Durometer Shore 00 [Approx.]45-5550-60—–—–30-4550-6060-70 
Shrinkage 7 Days @ 158o Max.5%5%5%5%3%3%3% 
K Factor0.380.380.250.300.250.230.30 
PolymerClosed Cell Silicone Sponge
AMS 31953196 
MIL MIL-R-46089MIL-R-46089 
25% Compression Deflection [psi]5-96-1412-2016-28
Density Approximate [pcf]31334045
Water Absorption Max. Weight %<1%<1%<1%<1%
Temperature Range oF-103 / +450-103 / +450-103 / +450-103 / +450
Temperature High Intermittent oF    
Ozone ResistanceExcellentExcellentExcellentExcellent
Tensile Strength [psi]GoodGoodVery GoodVery Good
Elongation Typical Properties %GoodGoodVery GoodExcellent
Thermal Conductivity BTU0.750.750.800.85
Dielectric Strength [approx]150 volts/mil150 volts/mil150 volts/mil150 volts/mil


Rubber is often referred to as a “solid elastomeric.” Generally speaking, the two most common types of rubber are natural and synthetic. Natural (gum) rubbers are derived from the rubber tree. Conversely, rubber-like materials from sources other than the rubber tree are commonly referred to as synthetic rubber.

Though there are currently more than 36 synthetic rubber compounds available, not all are commonly used. Rubber compounds have been researched, developed, and engineered to meet many application requirements, including fluid, temperature, and pressure resistance. Many synthetic rubber materials are also available with different degrees of reinforcement, such as cloth inserted (CI) or fabric reinforced (diaphragm). These materials are designed specifically to meet a variety of customer applications.

COMMON TRADE NAMES: Nitrile [Buna-N], Neoprene, Silicone, FKM [Viton®], EPDM, SBR, and many more.


  • Gaskets
  • Diaphragms
  • Seals
  • Chute Lining
  • Seats
  • Extrusions
  • Door Seals
  • Molded Seals [Shapes]
  • Tubing
  • Bumpers
  • Pads
  • Grommets
  • Washers
PolymersAcrylonitrile Butadiene RubberEthylene PropyleneFluoroelastomerSilicone
Common NamesBuna-N, Nitrile, NBREPR, EPT, EP, EPDMViton®, FKMVMQ
Mil-R-3065 [Mil-Std-417 ClassSBRSTBTA
General Characteristics
Durometer Range [Shore A]20-9530-9050-9510-85
Tensile Range [psi]200-3500500-2500500-2000500-2500
Elongation Range %350-650100-700400-500450-900
Compression Set ResistanceGood to ExcellentGoodGood to ExcellentExcellent
Resilience / ReboundGood to ExcellentFair to GoodPoor to FairGood
Abrasion ResistanceGood to ExcellentGoodFair to GoodGood
Tear StrengthGood to ExcellentFair to GoodFair to GoodGood
Solvent ResistanceGood to ExcellentPoorExcellentPoor
Oil ResistanceExcellentPoorExcellentPoor
Low Temperature oF-70-60-30-75
High Temperature oF+250+300+572+500
Ozone ResistanceFair to GoodGood to ExcellentExcellentExcellent
PolymersPolychloropreneStyrene Butadiene RubberFluorosiliconePolyisobutylene
Common NamesNeopreneSBRFVMQButyl
Mil-R-3065 [Mil-Std-417 ClassSERSTARS
General Characteristics
Durometer Range [Shore A]20-9530-9540-8040-90
Tensile Range [psi]500-3000500-2900500-1500500-2900
Elongation Range %100-800300-450150-600300-850
Compression Set ResistancePoor to GoodGood to ExcellentVery GoodFair to Good
Resilience / ReboundFair to GoodGoodGoodFair to Good
Abrasion ResistanceGood to ExcellentExcellentPoorFair to Good
Tear StrengthGood to ExcellentFair to ExcellentPoorGood
Solvent ResistanceFairPoorExcellentPoor
Oil ResistanceFairPoorGoodPoor
Low Temperature oF-70-60-100-70
High Temperature oF+250+250+450+300
Ozone ResistanceGood to ExcellentPoor to GoodExcellentExcellent

To learn more about rubber elastomeric materials from The Gund Company or request a quote for your application, Contact Us Today!


O-rings’ primary functions are to create a barrier between two items where air or fluid may escape. They are typically installed in a groove to hold them in place while squeezed between two opposite surfaces. In most cases, O-rings are sized using the inside diameter (ID) by Cross Section (CS). O-rings are particularly effective because they have memory and want to expand to their original size and shape. So, compressing them between two opposing surfaces creates an air or fluid-tight seal. O-rings are available in a variety of natural and synthetic rubber compounds. Depending on the application, the material chosen can significantly impact the functionality of the O-ring.

Though they are a common commodity, choosing the proper O-ring for the application can be challenging considering thermal resistance and degradation from fluid and gasses. Additionally, there are several standards for O-rings worldwide. The most common standard for North America is AS568. We understand the various mechanical properties of O-ring materials. Contact one of our material specialists today to review your applications or request a quote.

O-rings are available in most polymer compounds and sizes, including AS568B [chart below], Metric sizes, both molded and vulcanized endless from the O-ring cord. REQUEST A QUOTE


  • Hydraulics
  • Faucets
  • Gaskets
  • Setting Tools
  • Frac Plugs
  • Carburetors
  • Gas Valves
  • Helicopters
Cross SectionCross SectionCross Section
 1/163/321/83/16 1/163/321/83/161/4 3/321/83/161/4
1/32001*   2 3/16 139   7167262365441
3/64002*   2 1/4053140228331 7 1/4168263366442
1/16003102  2 5/16 141   7 1/2169264367443
5/64004   2 3/8036142229332 7 3/4170265368444
3/32005103  2 7/16 143   8171266369445
1/8006104  2 1/2037144230333 8 1/4172267370 
5/32007105  2 9/16 145   8 1/2173268371446
3/16008106201 2 5/8038146231334 8 3/4174269372 
7/32009107  2 11/16 147   9175270373447
1/4010108202 2 3/4039148232335 9 1/4175271374 
5/16011109203 2 13/16 149   9 1/2177272375448
3/8012110204 2 7/8040150233336 9 3/4178273376 
7/160131112053093041151234337 10 274377449
1/20141122063103 1/8  235338 10 1/2 275378450
9/160151132073113 1/4042152236339 11 276379451
5/80161142083123 3/8  237340 11 1/2 277380452
11/160171152093133 1/2043153238341 12 278381453
3/40181162103143 5/8  239342 12 1/2   454
13/160191172113153 3/4044154240343 13 279382455
7/80201182123163 7/8  241344 13 1/2   456
15/160211192133174045155242345 14 280383457
10221202143184 1/8  243346 14 1/2   458
11/160231212153194 1/4046156244347 15 281384459
11/80241222163204 3/8  245348 15 1/2   460
13/160251232173214 1/204715724634942516 282385461
11/40261242183224 5/8  24735042616 1/2   462
15/160271252193234 3/404815824835142717 283386463
13/80281262203244 7/8  24935242817 1/2   464
17/16 127221 504915925035342918 284387465
11/20291282223255 1/8  25135443018 1/2   466
19/16 129  5 1/405016025235543119  388467
15/80301302233265 3/8  25335643219 1/2   468
1 11/16 131  5 1/2 16125435743320  389469
13/40311322243275 5/8  25535843421  390470
1 13/16 133  5 3/4 16225635943522  391471
17/80321342253285 7/8  25736043623  392472
1 15/16 135  6 16325836143724  393473
20331362263296 1/4 16425936243825  394474
2 1/16 137  6 1/2 16526036343926  395475
2 1/80341382273306 3/4 166261364440     
  • Section Diameter of AS568-001 is 1/32                * Sectional diameter of AS568-002 is 3/64

To learn more about O-Ring materials from The Gund Company or request a quote for your application, Contact Us Today!

Visit our material datasheets Section for more information.

EMI Shielding / Thermal Management

EMI Shielding and Thermal Management are generally grouped together. They are commonly listed under similar industry specifications.

EMI Shielding: Electromagnetic Interference has become far more significant in recent years as the use of electronic devices continues to increase. As the utilization of these devices continues to grow, so does the exposure to a wide range of frequencies. Through years of research and development, manufacturers have determined that electrical insulation, enclosures, and cables are effective ways to contain these frequencies.

Organizations such as the CE & FCC have provided guidelines in the form of legal requirements to prevent electromagnetic interference (noise). As such, EMI Shielding has become a necessity in the electronics industry. Since there are a wide variety of application designs and frequency requirements, various materials have been developed to provide adequate shielding.

Thermal Management: Historically, thermal grease was used to create continuity between power sources and heat sinks. Unfortunately, this grease was not ideal in applications where ease of installation and cleanliness were paramount. These days, many applications utilize thermally conductive materials or thermal management in place of this grease.

Thermally conductive compounds contain fillers that maintain flexibility in service while providing continuity between the mating surfaces. In electronic equipment, air acts as an insulator and must be eliminated for optimum performance. Manufacturers of electronic devices want to establish an anaerobic environment to allow continuity between the power source and heat sink for proper performance. Such thermal management products create continuity within the component to optimize the heat dissipation from the power source.

Thermal management products are used in an expansive list of applications. As such, there are an equally wide variety of thermal management options available.

The Gund Company is well versed in EMI Shielding and Thermal Management Contact one of our material specialists today to review your applications or request a quote.


Cork and rubber products are instrumental in metal-to-metal joints. If a proper firmness material is selected, no allowance for the side flow needs to be made. The compressibility of cork and rubber can be used in place of more expensive non-compressible rubber seals. Some of the friction of cork is retained in these products and helps to reduce extrusion and slippage.

Cork and rubber products can easily contain sponged materials that conform to and compensate for minor flange irregularities. This characteristic is especially useful in stamped or other lightweight assemblies where the available bolt spacing and bolt load are usually low.

Cork/rubber products have an unusual resilience which helps resist compression set and other effects of fatigue. Cork and rubber seals are more resistant to aging than traditional rubber compounds.

Cork and rubber compounds are used to establish and maintain intimate contact between the flanges. The most common synthetic rubber compounds are Neoprene® and Nitrile. However, special applications may use cork material blended with Hypalon®, Silicone, Fluoroelastomer, SBR, or Vamac.

COMMON BRANDS: ECORE Intl, Amorim Cork Solutions
COMMON TYPES: Composition Cork, Cork & Neoprene, Cork & Nitrile, Cork & Sponged Rubber


  • Air Compressors
  • Air Pumps
  • Carburetors
  • Electric Motors
  • Fuel & Oil Pumps
  • Fire Hydrant Valves
  • Gear Boxes
  • Heat Exchangers
  • Meters
  • Pipe Flanges
  • Pumps
  • Transformers
  • Transmissions
Cork & Rubber Composition
PropertyTest MethodTypical ResultTypical ResultTypical ResultTypical Result
Polymer NeopreneNeopreneNitrileEPDM – Sponge
Density [ibs/ft3]ASTM D367635.737.539.931.5
Tensile Strength [lbs/in2]ASTM F152240355253135
Compression @ 100 psiASTM F36—-—-—-35%
Compression @ 400 psiASTM F3645%29%40%—-
Recovery 80%80%82%90%
Shore A HardnessASTM D22406360 to 8060 to 7054
FlexibilityASTM F1473 max3 max3 max3 max
Fluid ImmersionASTM F146    
Oil 1 [70 hrs @ 212oF] -5 to +15%-10 to +8%-5 to +10%-10 to +10%
Oil 3 {70 hrs @ 212oF] +5 to +50%+5 o 15%—-+15 to +50%
Fuel A [22 hrs @ 75oF] 0 to +35%0 to +15%—-0 to +25%
Compression Set BASTM D395    
25% deflection, 22 hrs @ 158oF 55% max65% max60% max90% max
Temperature Range oF -140 to +250-140 to +250-140 to +250-140 to +250
SpecificationASTM F104F227000 M1 TF226000 M2 TF227000 M2 TF226000 M1 T
Shelf Life 5 Years5 Years5 Years5 Years
Cork & Nitrile Composition
PropertyTest MethodTypical ResultTypical ResultTypical ResultTypical Result
Polymer NitrileNitrileNitrileNitrile
Density [ibs/ft3]ASTM D367640.145.952.630.5
Tensile Strength [lbs/in2]ASTM F152295325422120
Compression @ 100 psiASTM F3625%—–—–38%
Compression @ 400 psiASTM F3639%33%24% 
Recovery 81%82%81%90%
Shore A HardnessASTM D224060 to 7560 to 7560 to 8050
FlexibilityASTM F1473 max3 max3 max3 max
Fluid ImmersionASTM F146    
Oil 1 [70 hrs @ 212oF] -5 to +10%-5 to +10%-5 to +10%0 to +15%
Oil 3 {70 hrs @ 212oF] -2 to +15%-2 to +20%-2 to +15%+10 to +30%
Fuel A [22 hrs @ 75oF] -2 to +10%-2 to +10%-2 to +10%0 to +15%
Compression Set BASTM D395    
Cork & Neoprene Composition
PropertyTest MethodTypical ResultTypical ResultTypical ResultTypical Result
Polymer NeopreneNeopreneNeopreneNeoprene
Density [ibs/ft3]ASTM D367635.648.453.148.4
Tensile Strength [lbs/in2]ASTM F152218336400336
Compression @ 100 psiASTM F36—–—–—– 
Compression @ 400 psiASTM F3647%25%26%32%
Recovery 81%83%80%83%
Shore A HardnessASTM D22406165 to 7560 to 8065 to 75
FlexibilityASTM F1473 max3 max3 max2 max
Fluid ImmersionASTM F146    
Oil 1 [70 hrs @ 212oF] -2 to +10%-2 to +20%-2 to +20%+2 to +10%
Oil 3 {70 hrs @ 212oF] +5 to +30%+15 to +50%+15 to +50%+10 to +50%
Fuel A [22 hrs @ 75oF] 0 to +15%0 to +15%0 to +15%0 to +15%
Compression Set BASTM D395    
25% deflection, 22 hrs @ 158oF 60% max60% max55% max60% max
Temperature Range oF -40 to +250-40 to +250-40 to +250-40 to +250
SpecificationASTM F104—–F226000 M2 TF224000 M2 TF226000 M2 T
SpecificationAMS-C-6183TYP 1 CL 2 GR ATYP 1 CL 2 GR BTYP 1 CL 2 GR CTYP 1 CL 2 GR B
Shelf Life 5 Tears5 Tears5 Tears5 Tears
Composition Cork
Property Typical Result
Density [ibs/ft3]ASTM D367615.8
Tensile Strength [lbs/in2]ASTM F152125
Compression @ 100 psiASTM F3636%
Recovery 83%
FlexibilityASTM F1475 max
SpecificationASTM F104F217000RT
SpecificationHH-C-576BCl 1 TY II

To learn more about cork/rubber material from The Gund Company or request a quote for your application, Contact Us Today!

Visit our material datasheets Section for more information.

Felt & Wool

Natural wool felt is one of the oldest manufactured textiles. Many cultures have legends as to how the felting process was discovered. One of the earliest accounts of felting details how nomads fleeing persecution packed their sandals with wool to prevent blisters while crossing the desert. At the end of their journey, the movement and sweat had turned the wool into felt socks.

Felt is a textile material produced by matting, condensing, and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur or synthetic fibers such as petroleum-based acrylic or acrylonitrile, or wood-based rayon. Blended fibers are also standard. Felt has unique properties that allow it to be used for various purposes. “It is fire-retardant and self-extinguishing; it dampens vibration and absorbs sound, and it can hold large amounts of fluid without feeling wet.

Felt from wool is the oldest known textile. Many cultures have legends as to the origins of felt making. Sumerian legend claims that Urnamman of Lagash discovered the secret of felt making. The story of Saint Clement and Saint Christopher relates that the men packed their sandals with wool to prevent blisters while fleeing persecution. At the end of their journey, the movement and sweat had turned the wool into felt socks.

Today’s pressed wool felt is made via an intricate process called “wet processing.” Fibers are combined by applying pressure, moisture, and vibration, then carded and cross-lapped to make multiple material layers. The material’s ultimate thickness and density determine the number of steamed, wetted, pressed, and hardened layers.

In the wet felting process, hot water is applied to layers of animal hairs. Repeated agitation and compression cause the fibers to hook or weave into a single fabric piece. Wrapping the properly arranged fiber in sturdy, textured material, such as a bamboo mat or burlap, will speed up the felting process. The felted material may be finished by fulling.

Specifications: SAE/C-F-206G

The majority of fiber used in pressed felt is wool. Wool fibers have small barbs on them, which aids in the natural locking or felting process. The manufacturing of pressed wool felt is primarily mandated by SAE standards. These standards determine the wool content, density, and other physical and mechanical properties of the felt. Pressed wool felt is identified by the SAE standards F-1 thru F-26.

The lower the SAE numbers, the more machinable, have better vibration absorption, and better abrasion resistance. Wool felt has excellent wicking properties. It can absorb its weight in oil several times, and when used as a lubrication wick, it will supply small amounts of oil at a uniform rate. Pressed wool felt has excellent solvent resistance and stability in oil. SAE wool felt is unaffected by sunlight and maintains its original form after long periods of stress.

COMMON TYPES: Wool, Polyester, High Temperature


  • Gaskets
  • Wicking
  • Dust Shields
  • Grease Retainer
  • Sound Reduction
  • Wipers
  • Weather Stripping
  • Pads

US Federal Specification C-F-206G

Type 1 Roll Felt SAE No.F-1F-2F-3F-5F-7F-10F-11
Classification No.16R116R216R312R112R39R19R2
Wool Content %95908595809587
Chlorothene Solubles %
Water Solubles %
Total Solubles %
Ash Content %
Tensile Strength psi50050040025022520075
Slit Resistance psi332822181286
Width (inch)606060/7260727272
Type1 Roll Felt SAE No.F-13F-15NF-26NF-50F-51F-55
Classification No.9R49R58R516R1X16R3X12R3X
Wool Content %755545959275
Chlorothene Solubles %
Water Solubles %
Total Solubles %
Ash Content %
Tensile Strength psi757575500300200
Slit Resistance psi222332212
ColorGrayGrayGrayWhiteGrayGray or Black

Felt & Polyester

Polyester felt is a synthetic needle-punched felt made from polyester fibers. Material is normally supplied in either black or white. This general-purpose felt is made in various densities, ranging from .019” to 2”. Polyester felt is inexpensive and often made in comparable density and thickness to SAE pressed wool felt. The maximum temperature of polyester felt is 300oF, compared to 200oF for SAE pressed felts. This material can be used for filtration applications, gaskets, wipers, and padding in various industries. The density of polyester felt is commonly measured in ounces/sqyd.

Polyester felt is usually supplied in either black or white, in various densities and thicknesses ranging from .019” to 2.0” thickness.


  • Filtration
  • Gaskets
  • Weatherstripping
  • Wipers
  • Crate lining
  • Padding

To learn more about felt in wool or polyester material from The Gund Company or request a quote for your application, Contact Us Today!

Visit our material datasheets Section for more information.

Aramid fiber paper is characterized by exceptional temperature and tear resistance. This includes, but is not limited to, aramid papers, such as Nomex®, and 3M® inorganic paper products.

These papers can be formed into basic shapes to help line slots or make fitted bends on corners. Papers made from inorganic fiber are less expensive than aramid fiber papers and have better thermal conductivity. Typically, they are more brittle and can only be formed reliably when used as a laminate with a thermoplastic film.