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Cork Composition (Cork-Rubber) VMQ-CORK

Matrix

ASTM F104

Use when continuous service above 150 °C or wide-temperature-range sealing (ovens, transformers, aerospace ducts) is required.

Premium cost $$$

Values for the VMQ-CORK condition

Other Cork Composition (Cork-Rubber) tempers and conditions

Cork Composition (Cork-Rubber) is listed in 4 conditions; see the grade overview at Cork Composition (Cork-Rubber).

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
VMQ-CORKThis page
silicone rubber bonded cork composition (high temperature)
Use when continuous service above 150 °C or wide-temperature-range sealing (ovens, transformers, aerospace ducts) is required.—110—0.12 W/m·K
styrene-butadiene bonded cork composition (general purpose)
Lowest-cost grade for water, air and vibration-damping pads where oil resistance is not needed.—115—0.09 W/m·K
Neoprene (chloroprene) bonded cork composition
Pick for weathering, refrigerant, mild acid/alkali and outdoor electrical enclosure sealing.—214—0.1 W/m·K
NBR-CORKDefault
nitrile rubber bonded cork composition (ASTM F104 Type 5, oil resistant)
Default choice for oil, fuel and hydraulic-fluid gaskets: transformer covers, oil pans, gearbox and pump flanges.—212—0.1 W/m·K

What is Cork Composition (Cork-Rubber) VMQ-CORK?

Cork Composition (Cork-Rubber) VMQ-CORK is Cork Composition (Cork-Rubber) in the VMQ-CORK condition — use when continuous service above 150 °C or wide-temperature-range sealing (ovens, transformers, aerospace ducts) is required. Cork Composition (Cork-Rubber) VMQ-CORK has a tensile strength of 1 MPa (0.174 ksi), weaker than 96% of natural material grades. Elongation at break is 10% and the elastic modulus is 0.04 GPa (0.0058 Msi). Cork Composition (Cork-Rubber) VMQ-CORK has a density of 0.85 g/cm³ (0.0307 lb/in³), heavier than 70% of natural material grades. NBR-CORK is the default condition FabDigit quotes; VMQ-CORK is available on request or by drawing note.

Advantages

  • High service temperature — 230°C (446 °F), better than 85% of natural material grades
  • Ductile — tolerates forming and impact — 10%, better than 82% of natural material grades
  • Good corrosion resistance — 60/100, better than 77% of natural material grades

Limitations

  • Low stiffness — 0.04 GPa (0.0058 Msi), worse than 87% of natural material grades
  • High embodied carbon — 1.5 kg CO₂/kg, worse than 83% of natural material grades

Cork Composition (Cork-Rubber) VMQ-CORK properties

Typical room-temperature values for Cork Composition (Cork-Rubber) VMQ-CORK; 12 are specific to this condition. Other listed values are Cork Composition (Cork-Rubber) reference data and may not represent this condition. Bars are the position among natural material grades.

Physical2

Cork Composition (Cork-Rubber) VMQ-CORK has a density of 0.85 g/cm³ (0.0307 lb/in³), heavier than 70% of natural material grades.

Density0.85 g/cm³0.03 lb/in³
Porosity35%

Mechanical6

Cork Composition (Cork-Rubber) VMQ-CORK has a tensile strength of 1 MPa (0.174 ksi), weaker than 96% of natural material grades. Elongation at break is 10% and the elastic modulus is 0.04 GPa (0.0058 Msi).

Elastic (Young's) Modulus0.04 GPa0.01 Msi
Poisson's Ratio0.15
Tensile Strength (Ultimate)1 MPa0.17 ksi
Elongation at Break10%
Compressive Strength3 MPa0.36 ksi
Shear Strength0.8 MPa0.12 ksi

Thermal5

Cork Composition (Cork-Rubber) VMQ-CORK is rated for continuous service to 230°C (446 °F). It conducts heat at 0.12 W/m·K (0.0693 BTU/hr·ft·°F), worse than 70% of natural material grades. Thermal expansion is 120 µm/m·K (66.7 µin/in·°F).

Thermal Conductivity0.12 W/m·K0.07 BTU/hr·ft·°F
Specific Heat Capacity1,700 J/kg·K0.41 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)120 µm/m·K66.7 µin/in·°F
Max Service Temperature (continuous)230°C446 °F
Min Service Temperature-55°C-67 °F

Electrical2

Cork Composition (Cork-Rubber) VMQ-CORK is an electrical insulator with a dielectric strength of 4 kV/mm (101.6 V/mil) and a resistivity of 1×10¹¹ Ω·m.

Electrical Resistivity1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
Dielectric Strength4 kV/mm102 V/mil

Chemical & Environmental1

Corrosion resistance is good (60/100), better than 77% of natural material grades.

Corrosion ResistanceGood60/100

Sustainability4

Producing a kilogram of Cork Composition (Cork-Rubber) VMQ-CORK takes about 18 MJ of energy and emits 1.5 kg of CO₂ — more than 81% of natural material grades. Typical recycled content is 40%.

Embodied Energy (primary production)18 MJ/kg7,739 BTU/lb
Embodied Carbon (primary production)1.5 kg CO₂/kg
Embodied Water120 L/kg14.4 gal/lb
Typical Recycled Content40%

Manufacturability1

Cork Composition (Cork-Rubber) VMQ-CORK's machinability is very good (80/100, worse than 52% of natural material grades).

MachinabilityVery good80/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Cork Composition (Cork-Rubber) VMQ-CORK

Is Cork Composition (Cork-Rubber) easy to machine?

Best die-cut, steel-rule cut, punched or water-jet cut; router/knife cutting works but avoid hot high-speed tools that smear the binder.

Can Cork Composition (Cork-Rubber) be welded?

Not weldable; joints are made with butt or scarf splices bonded by contact/CR adhesive or by vulcanized splicing tape.

Can Cork Composition (Cork-Rubber) be formed, bent or molded?

Supplied as calendered/press-cured sheet or slit rolls; it conforms to irregular flanges at low bolt load — do not over-compress beyond about 50 % thickness.

What surface finishes work on Cork Composition (Cork-Rubber)?

Optional silicone or wax-based surface coating to reduce sticking and improve fluid release; adhesive backing (PSA) is common for stick-in-place gaskets.

Cork Composition (Cork-Rubber) chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
cork granulateground Quercus suber bark, typical 0.5–3 mm granule size45 – 7560
curatives, fillers and processing aidssulfur/peroxide cure system, carbon black or mineral filler2 – 85
elastomer binder (NBR/CR/SBR/VMQ)type sets oil/temperature resistance≥ 20 (balance)—

Cork Composition (Cork-Rubber) VMQ-CORK — frequently asked

What is Cork Composition (Cork-Rubber) VMQ-CORK used for?

Cork Composition (Cork-Rubber) VMQ-CORK is typically used for engine gaskets, oil seals, expansion joints and vibration pads. In short: conforms at low bolt load; oil-resistant cork gasket sheet; ASTM F104 line-call grades.

What is the tensile strength of Cork Composition (Cork-Rubber) VMQ-CORK?

Cork Composition (Cork-Rubber) VMQ-CORK has a typical tensile strength of 1 MPa (0.174 ksi) — weaker than 96% of natural material grades. Strength varies by condition: see the 4 listed tempers.

Is Cork Composition (Cork-Rubber) VMQ-CORK easy to machine?

Yes — machinability is rated very good (80/100, worse than 52% of natural material grades). Best die-cut, steel-rule cut, punched or water-jet cut; router/knife cutting works but avoid hot high-speed tools that smear the binder.

Can Cork Composition (Cork-Rubber) VMQ-CORK be welded?

Not weldable; joints are made with butt or scarf splices bonded by contact/CR adhesive or by vulcanized splicing tape.

What surface finishes work on Cork Composition (Cork-Rubber) VMQ-CORK?

Optional silicone or wax-based surface coating to reduce sticking and improve fluid release; adhesive backing (PSA) is common for stick-in-place gaskets.

Can Cork Composition (Cork-Rubber) VMQ-CORK be formed, bent or molded?

Supplied as calendered/press-cured sheet or slit rolls; it conforms to irregular flanges at low bolt load — do not over-compress beyond about 50 % thickness.

What is the maximum service temperature of Cork Composition (Cork-Rubber) VMQ-CORK?

Cork Composition (Cork-Rubber) VMQ-CORK is rated for continuous use to about 230°C (446 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. ASTM F104 — Standard Classification System for Nonmetallic Gasket Materials — ASTM International (2023)
  2. ASTM F36 / F152 / F146 — compressibility-recovery, tensile and fluid immersion tests for gasket materials — ASTM International (2021)
  3. Cork-rubber gasket sheet datasheets (nitrile, neoprene, SBR and silicone bonded grades) — Gasket sheet producers (2023)
  4. Cork: Biology, Production and Uses (properties of cork composites) — Elsevier (2015)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.