Gasket Materials
Guide

Every gasket we sell is built from verified, tested material. This guide breaks down what each material is, how it's constructed, and what testing backs it up — so you know exactly what you're putting in your engine.

Verified Composition XRF analysis confirms alloy content on metal components
Heat Tested Materials rated for sustained high-temperature engine use
Fluid Resistant Tested against oils, fuels, coolants, and ATF
Full Data Sheets Download the complete technical spec sheet for each material

Material Profiles

9 materials
Fiber / Soft

Cellulosic Fiber Gasket Material

Asbestos-free composite of cellulosic and thermoresistant fibers bonded with NBR rubber. Designed for cylinder head gaskets in gasoline and diesel engines.

Graphite / Surface TreatmentAnti-stick coat
Cellulosic + Thermoresistant FibersPrimary structure
NBR Rubber BinderSealing compliance
Cellulosic + Thermoresistant FibersPrimary structure
Graphite / Surface TreatmentAnti-stick coat
Density 1.10 g/cm³
Compressibility >30%
Creep Strength >38 MPa
Asbestos-free
Full spec sheet available View Data Sheet
Rubber on Metal

FKM Rubber on Stainless Steel — High Heat Grade

FKM (Viton) rubber coating on full-hard stainless steel core with graphite surface treatment. Built for automotive head gasket applications requiring maximum heat and fluid resistance.

Graphite Surface TreatmentAnti-stick
FKM Rubber Coating0.025 mm per side
Stainless Steel Core (Full Hard)0.20 mm nominal
FKM Rubber Coating0.025 mm per side
Graphite Surface TreatmentAnti-stick
Total Thickness 0.25 mm
Tensile Strength 1,320 N/mm²
Rubber Hardness 91 Shore A
Rubber Type FKM "L"
Full spec sheet available View Data Sheet
Metal Core

Cold Rolled Stainless Steel

Full-hard austenitic stainless steel strip produced to JIS G 4313. Used as the structural metal core in multi-layer and metallic gaskets — providing high spring-back and fatigue resistance.

Cold Rolled Stainless Steel — Full Hard0.200 mm
Tensile Strength 1,273 N/mm²
Hardness 370–400 Hv
Ni 6.56%
Cr 16.75%
Thickness 0.200 mm
Full spec sheet available View Data Sheet
Rubber Coating

FKM (Viton) Rubber

Premium fluorocarbon rubber with outstanding heat, oil, and chemical resistance. Used as the rubber coating on metallic gaskets and as sealing material in demanding engine environments.

FKM Fluorocarbon RubberShore A 75 — High Heat Grade
Hardness Shore A 73
Tensile Strength 1,673 psi
Elongation 182%
Heat Resistance 250°C / 70 hrs
Comp. Set 17% @ 200°C
Full spec sheet available View Data Sheet
Foam

Foam Rubber on Steel Core

Foamed rubber surface bonded to an SPCC steel core with graphite coating. The foam layer absorbs flange roughness and seals at low pressures — ideal where surface finish isn't perfect.

Graphite CoatAnti-stick
Foam Rubber LayerHigh compressibility
AdhesiveBonds rubber to core
SPCC Steel CoreStructural backbone
AdhesiveBonds rubber to core
Foam Rubber LayerHigh compressibility
Graphite CoatAnti-stick
Seals rough flanges
Bead compatible
Low creep relaxation
Full spec sheet available View Data Sheet
Rubber on Metal

NBR Rubber on Steel

Nitrile (NBR) rubber coating bonded to cold rolled steel core. A versatile general-purpose gasket material with strong resistance to oils, coolants, and transmission fluids.

NBR-75 Rubber CoatingOil & fuel resistant
Cold Rolled Steel Core (1/4 Hard)0.254 mm nominal
NBR-75 Rubber CoatingOil & fuel resistant
Composite Thickness 0.488 mm
Compressibility 0–5%
Recovery 50–98%
Creep Relaxation 10% max
Full spec sheet available View Data Sheet
Rubber on Metal

FKM Rubber on Stainless Steel

FKM (Viton) rubber coating on SAE 301 full-hard stainless steel. Rated to 200°C for 500 hours with no loss of adhesion — the highest heat and fluid resistance in our lineup.

FKM (Viton) Rubber Coating0.025 mm per side
SAE 301 Full Hard Stainless Steel0.203 mm nominal
FKM (Viton) Rubber Coating0.025 mm per side
Heat Resistance 200°C / 500 hrs
Compression 20% max
Recovery 90% min
Bond Rating 5B — No Loss
Full spec sheet available View Data Sheet
Foam

Foamet Sponge Rubber Sheet / Metal Core

NBR foamed rubber coating bonded to a cold rolled steel core. The sponge surface conforms to irregular flanges and seals at low clamp loads — ideal where surface finish isn't perfect.

NBR-50 Foamed CoatingSponge rubber — conforms to rough surfaces
Cold Rolled Steel Core1/4 Hard — structural backbone
NBR-50 Foamed CoatingSponge rubber — conforms to rough surfaces
Spec MS-18638
Rubber NBR-50 Foamed
Core CR Steel 1/4 Hard
Fluid Resistant
Full spec sheet available View Data Sheet
Rubber on Metal

NBR Rubber-Graphite Coated Steel

NBR rubber coating on SPCC-4 cold-rolled carbon steel core with graphite surface treatment. Oil, fuel, and coolant resistant — built for standard automotive engine gasket applications.

Graphite Surface TreatmentAnti-stick
NBR “R” Rubber Coating0.065 mm per side
SPCC-4 Cold-Rolled Steel Core0.25 mm nominal
NBR “R” Rubber Coating0.065 mm per side
Graphite Surface TreatmentAnti-stick
Total Thickness 0.38 mm
Hardness 75 Shore A
Tensile 7.55 MPa
Spec RS-3825
Full spec sheet available View Data Sheet

How We Test

Heat Resistance

Materials are exposed to sustained high temperatures to verify they maintain structural integrity, hardness, and sealing performance under real engine conditions.

ASTM A1-10 DIN 52913 250°C × 70 hrs

Fluid Resistance

Gasket materials are submerged in engine oil, fuel, coolant, ATF, and PAG oil. Weight and thickness change are measured to confirm the material won't swell or degrade in use.

ASTM F-146 WTM-116 WTM-117

Compressibility & Recovery

Measures how much a gasket compresses under bolt load and how much it springs back. Critical for maintaining a reliable seal without blowing out or going flat over time.

ASTM F-36 WTM-138 ASTM D-575

Creep Relaxation

Tests how much a material permanently loses clamping load over time at elevated temperatures — a key indicator of long-term sealing reliability in hot engine environments.

ASTM F-38 212°F / 22 hrs

Tensile Strength

Both the metal core and rubber coating are tested for tensile and elongation properties. Ensures the gasket can withstand clamp loads and thermal cycling without tearing.

ISO 1924/2-97 JIS G 4313

Rubber-to-Metal Bond

For coated metal gaskets, the bond between the rubber layer and the metal core is tested for integrity against solvents, water, and coolant to ensure the coating won't delaminate.

WTM-122 ASTM D-3359 5B Rating