Gasket and Sealing Materials - I. G. Marston Co., Inc.

Gasket and Sealing Materials

All Materials Are RoHS and DFARS Compliant!
*Click Material Title to Download MSDS and Technical Data Sheets*

I.G. Marston Co., Inc., since 1844, has experienced engineering and processing capabilities to offer a wide range of solutions to sealing problems. With many materials to choose from, ranging from standard grades to the most advanced which can seal, insulate or shim the most challenging of applications and with the most demanding requirements.

We manufacture and produce an array of products using these materials including:

Sealing Products:

  • Gaskets
  • Diaphragms
  • Insulators
  • Shims
  • Thermal Pads
  • Spacers
  • Washers
  • Custom Shapes
  • Seals
  • End Laminations
  • Discs


  • Automotive
  • HD Truck
  • Meters
  • Medical
  • Compressors
  • Aerospace
  • Electronic
  • Appliance
  • Pumps
  • Agriculture
  • Construsaction
  • Filters
  • Small Engine
  • Transmission
  • Valves
  • Controls
  • Gauges
  • Security
  • Light Systems
  • Plumbing

Various Brands and Grades we machine are below! Please inquire if you do not see a material you need machined components made from:

Nitirle/Nylon materials are generally resistant to hydrocarbons, hydraulic fluids and chemicals. The temperature ranges from -65° to +275° F. Materials meet Federal Standard 191A or ASTM

Grades/Characteristics and Applications:

Double coated nitrile on nylon cured
Gaskets & Diaphragms

D/C nitrile/nylon cured
Diaphragm material

D/C nitrile on nylon cured
Mechanical Diaphragms & Gaskets

Double coated nitrile on nylon
Mechanical Diaphragms & Gaskets

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Copaco is a very robust electrical insulation product and is normally supplied with a high density, very smooth “Glazed Roll” finish which eases the insertion into slot cells. The product is well suited to be punched, formed or creased.

Copaco electrical insulating rag papers are manufactured from only high-grade new cotton cuttings, the stock is extensively cleaned and specially refined to insure maximum purity and physical strength. No sizing, clay, fillers, or other chemical additives are used in Copaco. The absence of impurities ensures that Copaco’s aging characteristics will meet your most exacting requirements.

Electrical Insulating Paper 105° C.
Copaco is available from .003″ to .060″ in rolls, sheets, or coils slit to your specifications
Low compression and tension set
High tensile, tear, burst and dielectric properties
Excellent abrasion resistance

Slot liners for fractional HP motors
Windshield wiper motors
Power tools
Safety Shields
Transformer parts
Polyester film coated slot liners
Blower, fuel pump and power window motors
Saws, Drills, Shop Vacs, Light Ballasts
Terminal strip mounting boards

The proprietary cork/rubber matrix offered by DayStrong traces its roots to the Armstrong Cork Company. These products are recognized throughout the industry as the premium material for various gasket and sealing applications, and are found in uses such as off-road vehicles, oil patch, and aerospace. DayStrong materials exhibit outstanding abrasion and oil resistance.

Grades/Characteristics and Applications:

Cork rubber which consists of a vulcanized material prepared from granulated cork and a sponged synthetic rubber binder. The cork and rubber is intimately mixed and the compound is calendered. It has a cotton backing keyed into the undersurface to add stability and can be specified with or without pressure sensitive adhesive backing.

Cork rubber

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(Gasket and Sealing Materials)
Grades/Characteristics and Applications:


This gasketing material provides a tighter seal, with reduced product loss and emissions and improved performance over conventional PTFE. It is offered in the largest sheet sizes in the industry and cuts costs through reduced fluid loss, inventory costs, energy consumption, waste and maintenance.

  • Unique manufacturing process minimizes cold flow problems
  • Excellent bolt torque retention
  • These materials withstand a wide range of chemicals for extended service life in a wide variety of applications

Style 3545 – Microcellular PTFE with rigid inner core, Max. pressure 1200 PSI, Temperature range from -450° F (-265° C) to +500° F (+260° C), White w/Black Brand, Suitable for many non-metallic flanges, Highly compressible so it conforms to surface irregularities.

Style 3500 – PTFE w/silica filler, Max. pressure 1200 PSI, Temperature range from -450° F (-265° C) to +500° F (+260° C), Fawn w/Black Brand

Style 3504 – PTFE w/silica filler, Max. pressure 1200 PSI, Temperature range from -450° F (-265° C) to +500° F (+260° C), Blue w/Black Brand

Style 3510 – PTFE w/barium sulfate composition, Max. pressure 1200 PSI, Temperature range from -450° F (-265° C) to +500° F (+260° C), Off-white w/Black Brand


This gasketing has a unique blend of aramid fibers, fillers and elastomeric binders that provides improved torque retention and drastically lowered emissions levels. A variety of elastomers excel in a wide range of services. BLUE-GARD® cuts operational costs through reduced waste, fluid loss, maintenance, energy consumption and stocked inventory.

Style 3000 – Blue color, nitrile (NBR) binder, Max. pressure 1000 psig (70 bar), Temperature range from -100° F (-73° C) to +700° F (+371° C), For water, aliphatic hydrocarbon, oil and gasoline applications.

Style 3200/3400 – Off-white/grey-black color, SBR binder, Max. pressure 1200 psig (83 bar), Temperature range from -100° F (-73° C) to +700° F (+371° C), For water, saturated steam and inert gases (meets MIL-G-24696A).

Style 3300 – Off-white/grey-black color, SBR binder, Max. pressure 1200 psig (83 bar), Temperature range from -100° F (-73° C) to +700° F (+371° C), For water, saturated steam, refrigerant, oil and fuel applications.

Style 3700 – Light grey color, EPDM binder, Max. pressure 1200 psig (83 bar), Temperature range from -100° F (-73° C) to +700° F (+31° C), For water, saturated steam, and mild chemicals.

Style 3760 (Multi-Swell™) – Blue/off white color, synthetic fibers with a proprietary rubber binder, Max. pressure 500 psig (34.5 bar), Temperature range from -100° F (-73° C) to +400° F (+204° C), More universal than gaskets that swell in oil only, performs well in flanges that may crush an elastomer gasket which provides use in a wide array of applications.
Over 70% of gasket failures are due to lack of load. MULTI-SWELL™ gaskets react with water or oil to create their own load, creating a compressive load in light weight flanges. Basically, it seals where standard gaskets won’t. Problems with low load applications and leakage are a thing of the past.


Available in both PTFE and EPDM versions, this gasketing features raised, molded-in sealing rings that seal with 75% less surface area, for high performance in non-metallic flanges. Both types are suitable for use with acids, caustics, gases, water and hydrocarbons, while the EPDM version can also be used with water, very mild acids and caustics.

  • Pure PTFE sealing surface resists a variety of chemicals
  • Contaminant-free EPDM is ideal for pure service – electronics, pharmaceutical and food industries
  • Proprietary process bonds PTFE to elastomer, won’t delaminate or leach

STYLE ST-706 (Compressed Inorganic Fiber Gasket Material)

This versatile gasket material is ideal for standard ANSI flanged connectors, as well as turbine crossover piping connectors. It is suitable for steam, oil, grease, water and heat transfer fluids in power generation, chemical processing, hydrocarbon processing and other industries.

  • White in color, nitrile binder
  • Inorganic, asbestos-free fibers offer superior performance in saturated and superheated steam
  • Thermally stable fibers retain effective seal even during thermal cycling to 750° F (399° C)
  • Unique manufacturing process minimizes cold flow and creep relaxation problems
  • Temperature range of -100° F (-73° C) to +1000° F (+538° C)
  • Maximum pressure 1500 psig (104 bar)

STYLE 9900 (Graphite Fiber Gasket Material)
Tough and reliable, this graphite fiber gasket material withstands extreme temperatures and pressures, as well as many chemicals. Patented graphite fiber sheet is easy to handle and install. It is ideal for saturated steam, water, inert gas, aliphatic hydrocarbon, oil, gasoline and most refrigerant applications.
Mahogany color, graphite with nitrile composition
Maintains superior seal during thermal cycling, even in saturated steam and hot oils
Significantly reduces emissions to meet stringent Clean Air Act requirements
Temperature range of -100° F (-73° C) to +1000° F (+538° C)
Maximum pressure 2000 psig (138 bar)

IMPERVAPAC™ (Gasket Material)

Impervapac N-8051 gasket material offers a superior alternative to rubber and cork-rubber gaskets in low flange pressure sealing applications. A unique fiber composition with high rubber content makes Impervapac an ideal choice for sealing gases and fluids, while permitting reduced thickness for additional economy.

Grades/Characteristics and Applications:


Recommended for low internal pressure and low flange pressure applications up to 13.8 MPa (2000 psi ). Moderate oil resistance contains no asbestos. Nitrile butadiene binder. For applications up to 180°C (350°F).

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(Compressed Gasket Materials)

A wide range of material grades with fibers and binders in a variety of performance characteristics for compatibility with specific chemicals, pressures and temperatures.

Grades/Characteristics and Applications:


Synthetic Fiber
Nitrile Binder
Good sealabilty
Good chemical resistance
General purpose sheet


Synthetic Fiber
Nitrile Binder
Excellent sealability
Good creep relaxation
Excellent chemical resistance
Good general purpose sheet


Fiberglass, Aramid & Inorganic fillers
Nitrile Binder
Excellent creep relaxation
Ultimate Steam sheet
Outstanding Load Bearing
Best general purpose sheet


Carbon Fiber
Nitrile Binder
Good Steam sheet
High temperature
High Internal pressure
Suitable for a wide range of Chemical Applications


also available specs upon request:
C-4439, C-4509, C-5400, C-6327, C-6400, C-7400, C-8200

It has the right balance of properties for use in transformers, motors, generators and other electrical equipment. NOMEX® is a synthetic aromatic polyamide polymer that provides high levels of electrical, chemical and mechanical integrity, when converted into its various sheet forms. Used properly, NOMEX® products can extend the life of electrical equipment, reduce premature failures and repairs, and act as a safeguard in unforeseen electrical stress situations.

Within the family of NOMEX® products – papers, pressboards, non-wovens, fabricated parts and specialized forms – there is a solution to meet your particular requirements.

NOMEX® (Papers)

Grades/Characteristics and Applications:

TYPE 410
This is the original form and is widely used in a majority of electrical equipment applications. It is produced in thicknesses from 0.05 to 0.76 mm (2 to 30 mil) with specific gravities from 0.7 to 1.2. As a calendered product, it has high inherent dielectric strength, mechanical toughness, flexibility and resilience. NOMEX® Type 410 is used in almost every known sheet
insulation application.

TYPE 411
It is the uncalendered precursor of NOMEX® Type 410. It is available in thicknesses from 0.13 to 0.58 mm, (5 to 23 mil) with a specific gravity of 0.3 and correspondingly lower electrical and mechanical properties. It is used in applications such as motor phase insulation and transformer coil end filler, where high bulk and conformability are of prime importance along with increased impregnability and saturability.

TYPE 414
is electrically and thermally similar to NOMEX® Type 410, but is calendered under different conditions which produce a strong, but more flexible and conformable sheet with an open surface. It is produced in thicknesses from 0.09 to 0.38 mm (3.4 to 15 mil) with specific gravities from 0.9 to 1.0. It is designed for use as slot insulation in hand wound motors, for linear wrapping of wire, and as main insulation of fluid-filled and dry type transformers where conformability and impregnability are required.

TYPE 418
is produced by adding 50 percent mica platelets, intimately blended with the floc and fibrids during papermaking. It is available in thicknesses from 0.08 to 0.36 mm (3 to 14 mil) and is designed for high-voltage applications, including motor conductor and coil wrap, and transformer ground and layer insulation. NOMEX® Type 418 is a calendered product with high inherent dielectric strength (30 to 40 kV/mm) (760 to 1015 V/mil), but can also be readily impregnated with varnishes where this is desirable. NOMEX® Type 418 offers increased voltage endurance when compared to NOMEX® Type 410.

TYPE 419
is the uncalendered precursor of NOMEX® Type 418. It is available in two thicknesses, 0.18 mm (7 mil) and 0.33 mm (13 mil), with a specific gravity of 0.5 for applications where conformance and saturability are required.

is a medium-density paper (specific gravity 0.7) produced in thicknesses from 0.13 to 0.51 mm (5 to 20 mil). This calendered paper has mechanical and electrical properties intermediate between NOMEX® Type 410 and NOMEX® Type 411. It offers a higher yield and therefore economically a more attractive solution in applications where it is not critical to use to the full extent the mechanical or electrical properties of NOMEX® Type 410.
NOMEX® (Pressboards)

Increased thickness and rigidity set NOMEX® pressboards apart from the other forms of NOMEX.® They are used for spacers and barriers in transformers, both fluid-filled and dry type, and as end-laminations in motors. This family of products offers a range of mechanical properties which insures design flexibility in a variety of applications.

TYPE 992
is a low-density pressboard produced in two thicknesses (1.6 and 3.2 mm) (63 to 125 mil) with a specific gravity of 0.5. This material’s low density allows easy formation of complex shapes and provides the highest saturability of the pressboard products.

TYPE 993
is a medium-density pressboard produced in thicknesses from 1.0 to 4.0 mm (40 to 160 mil) with specific gravities of 0.7 to 0.9. This material provides a balance of rigidity and conformability along with outstanding saturability and excellent properties in oil.

TYPE 994
is a densified version of NOMEX® Type 993, available in thicknesses from 1.0 to 9.6 mm (40 to 380 mil) with specific gravities from 1.1 to 1.2. It provides superior stability under compressive loads. NOMEX® Type 994 will also absorb oils and other fluids, but not as readily as NOMEX® Types 992 and 993.

This general purpose grade is un-reinforced and offers the highest elongation and toughness of all PEEK grades. Unfilled PEEK is available in sheet and rod forms in natural (a very light brown or tan) color (see photo above) and is also available in black . Black PEEK is ideal for instrument components where aesthetics are important, as well as for seal components where ductility and inertness are important. All unfilled PEEK grades comply with FDA regulation 21 CFR 177.2415 for repeated food contact.

PEEK (30% Carbon Filled)
The addition of carbon fibers enhances the compressive strength and stiffness of PEEK, and dramatically lowers its expansion rate. It offers designers optimum wear resistance and load carrying capability in a PEEK-based product. This grade provides 3½ times higher thermal conductivity than unreinforced PEEK — dissipating heat from the bearing surface faster. Carbon-filled PEEK is black in color.

PEEK (Bearing Grade, Ketron HPV)
This grade of PEEK, containing carbon fiber reinforced with graphite and PTFE lubricants, offers the lowest coefficient of friction and the best machine ability for all PEEK grades. Bearing grade PEEK has an excellent combination of low friction, low wear, high limiting PV, low mating part wear, and easy machining. Bearing grade PEEK is black or dark grey in color.

Excellent chemical resistance
Very low moisture absorption
Inherently good wear and abrasion resistance
It carries a V-0 flammability rating and exhibits very low smoke and toxic gas emission when
exposed to flame.
Unaffected by continuous exposure to hot water or steam

Hot Water, Steam applications
Connector bodies
Medical applications

Reemay (formerly a DuPont product now produced by Reemay, Inc.) is a spun-bonded polyester material with the same chemical properties as polyester film. (Polyester fibers are mated together with heat, pressure and water to form an inert opaque material). Since it is the same polyester material, it can be heat-sealed to the film to give a porous side to a pouch. Pouches with the Reemay backing are used by many photo collectors.

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Santoprene™ thermoplastic vulcanizates (TPVs) are high-performance elastomers that combine the best attributes of vulcanized rubber – such as flexibility and low compression set – with the processing ease of thermoplastics. Santoprene™ is a registered trade mark of Exxon Mobil. It is the mixture of in-situ cross linking of EPDM rubber and polypropylene. It is supplied as pre-compound material which is able to process by conventional thermoplastic tools. Santoprene is a thermoplastic compound that is processed in much the same way as any type of plastic.

The difference is that Santoprene possesses the same levels of flexibility and durability that are commonly found with natural rubber compounds. Because of the longer life of santoprene in both extreme hot and cold environments, the material is often preferred over the use of rubber.


  • Temperature range from -60°C to 135°C (-81°F to 275°F) with no cracking or tackiness.
  • Santoprene TPVs range from supple 35 Shore A to tough 50 Shore D
  • General purpose grades are suitable for most applications.
  • FDA-compliant, NSF-listed and medical grades are also available.
  • Flame-retardant grades meet UL requirements.
  • Select from more than 20 grades that bond with ETPs, nylons, metals and various polyolefins.

In consumer and industrial product applications, the combination of Santoprene TPV properties and ease of processing delivers improved performance, consistent quality and lower production costs. In Automotive applications, the lighter weight of Santoprene TPVs contributes to improved efficiency, fuel economy and reduced costs. They also offer numerous benefits in appliance, electrical, construction, healthcare and packaging applications.

Syntheseal® materials are a direct substitute for asbestos-containing materials. Designed for use up to 180°C (350°F), these materials service a wide range of pressures and internal fluids. They are a proven substitute for joint sheet and asbestos-containing beater-addition products.

Grades/Characteristics and Applications:

This material is a direct substitute for compressed asbestos and asbestos-containing beater addition products. It is designed for low-to-moderate flange pressures at temperatures above 180°C (350°F) and is suitable for dry heat applications, electrical fixtures, and other light duty appliances. It can also be used as a radiant heat shield in applications where some degree of insulation is needed.

This is used in automotive, small engine, and compressor applications. It has excellent crush resistance at high flange pressures, and excellent sealing properties with oil, fuel, and water. It is intended for applications with short duration maximum temperatures up to 180oC (350oF).

An economical material exhibiting very good crush resistance at high flange pressures. Recommended for sealing oils, fuels, and water up to 180°C (350°F), and it is a fully cured nitrile binder.

This reinforced fiber material with a latent cured nitrile binder composition, with outstanding sealing characteristics. It has excellent oil resistance and applications up to 180°C (350°F).

It is controlled-swell, Latent cure styrene butadiene bound material with reinforced cellulose fiber. It is intended for applications sealing oil, fuel, and low-pressure steam with short duration maximum temperatures up to 180oC (350oF).

Thermo-Tork materials outperform many more expensive alternative products in a wide range of higher temperature, heavy-duty applications. Designed for use up to 400°C (750°F), Thermo-Tork materials are offered with either a Fully Cured or a Latent Cure thermally stable binder system and are made with heat-resisting fibers.

Grades/Characteristics and Applications:

Fully Cured binder, highly compressed material with good tensile strength, low creep relaxation, excellent fuel and oil resistance. For high flange pressure applications up to 400°C (750°F).

A heavy-duty. Latent Cure material with nitrile binder for heavy-duty applications at elevated temperatures up to 400°C (750°F). Excellent oil resistance.

Cost-effective heavy-duty compressed material with Fully Cured nitrile binder. Excellent fuel and oil resistance. Good tensile strength. For high flange pressure applications up to 350°C (650°F).

Cost-effective heavy-duty material Latent Cure system with nitrile binder. Good conformity for irregular flange surfaces. For applications up to 350°C (650°F).

Cost-effective heavy-duty compressed material with Fully Cured styrene binder. Recommended for use in oil, water, or steam. Good tensile strength. For service in high flange pressure applications up to 350°C (650°F).

Controlled-Swell alternative to high-swell compressed asbestos materials. Latent cure styrene binder on heat-resisting thermally stable fibers offers good sealing characteristics at low flange pressures. Conforms well to irregular flange surfaces. For applications up to 350°C (650°F).

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(Soft Gasket Materials)

In the 1890’s, a professor of chemistry at Amherst College discovered that certain paper, when impregnated with a solution of glue and glycerin, was transformed into a crackle parchment-like material that was waterproof, oil proof and greaseproof. Because of its parchment-like quality, the material was called “Vellumoid” (meaning “like vellum or parchment”). Since our humble beginnings, Vellumoid Incorporated has become a major producer of gaskets for automobiles, trucks, and miscellaneous sealing applications.

Grades/Characteristics and Applications:

Branded Vellumoid
Treated cellulose fiber material impregnated with a protein glue and glycerin binder. A general purpose gasket material with service temperatures up to 250°F.UL listed.

505 Fiber
Economical treated fiber material impregnated with a protein and glycerin binder. Materials best services in moderate duty applications at temperatures up to 250° F.

Velbuna WG-5
A nitrile rubber and cellulose fiber high density beater addition material. Highly resistant to oils, fuels, greases, water and coolants and it demonstrates maximum resistance to heat aging at service temperatures up to 300° F.

Velbuna WG-25
A blended rubber and cellulose fiber medium density beater addition material. It demonstrates good resistance to oils, water coolants and salt solutions. at service temperatures up to 300° F.

Velbuna WG-57-G
An economical low density cellulose and styrene butadiene rubber beater addition material. WG-57-G is a tough, versatile material intended for applications where a low cost beater addition type material is indicated at service temperatures up to 350° F.

Vellutherm 600
A nonasbestos beater addition material designed to function as a high swell gasket material when exposed to petroleum oils and fuels. Vellutherm 600 is formulated with a special blend of elastomers to provide an optimum balance of properties at service temperatures up to 350° F.

Vellutherm 611
A nonasbestos beater addition material consisting of a unique blend of fibers and other components with a cured nitrile rubber binder. Vellutherm 611 demonstrates high compressive strength and excellent dimensional stability under varying ambient humidities at service temperatures up to 350° F.

Vellutherm 650
A nonasbestos beater addition material consisting of blended fibers with a cured nitrile binder. Vellutherm 650 is an economical medium density material for use in general automotive and industrial applications at service temperatures up to 350° F.

It is a hard, highly densified fiber material with a nitrile rubber coating on both sides. Bucote is designed for use in rigid flange applications when spacing of component parts is critical.

Velcar B-10
This is a treated fiber base material with a nitrile rubber coating on both sides. Velcar is highly resistant to oils, gasoline, diesel and heating fuels at temperatures up to 250° F.

A specially designed material designed for difficult sealing applications. It approaches the sealing qualities of rubber, but has true compressibility. Nicote is composed of a rubber treated cellulose fiber base with a nitrile rubber coating on both sides. It demonstrates excellent resistance to gasoline, fuel oils, water and a number of solvents at service temperatures up to 300° F.

Nitrile butadiene rubber binder for fluid resistance Generally suitable for oil, gasoline and water services. For applications up to 180°C (350°F).

Cork and aromatic-fuel-resistant synthetic rubber.
Like DC-100, but with maximum oil and solvent resistance. UL-Listed.

This material was introduced in 1957 to meet the needs in the aerospace industry for a high-performance elastomer. Since then, the use of Viton® has spread quickly to many other industries, especially in the automotive, fluid power, appliance and chemical industries. With over 50 years of field-proven excellence, Viton® has developed a reputation for its outstanding performance in very hot and extremely corrosive environments.

Particularly valued for its excellent heat stability (200°C) and resistance to aggressive fuels and chemicals, Viton® is the most specified fluoroelastomer for fuel system seals and hoses, O-rings, shaft seals, expansion joints and gaskets. The latest types of Viton® are versatile, offering improved capabilities in steam, solvents, highly caustic environments and low temperatures. Because it extends the thermal resistance of mid-performance elastomers, Viton® is used extensively in aggressive automobile fuel systems, aircraft and chemical processing environments. Viton® is the first fluoroelastomer to achieve worldwide ISO 9000 registration.

DuPont™ Viton® consists of essentially several standard and specialty types of polymers based on their composition and fluorine content. The types differ primarily in the end-use performance of parts made from Viton®. Each type differs in its ability to: resist permeation and volume increase, resist attack and property degradation caused by the chemicals and fluids.

Grades/Characteristics and Applications:

General purpose sealing: Automotive, Aerospace fuels & lubricants

Used in chemical processing, power, utilities. Seals & Gaskets

Oxygenated automotive fuels, concentrated aqueous inorganic acids, water and steam

Automotive & Off-Road (High pH requirements)

Oil Exploration/Production, Special sealing requirements for harsh environments

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