VMQ Silicone O-Rings
Manufacturer & Custom Solutions

VMQ Silicone O-Rings

VMQ silicone O-rings from ZSR Silicone Parts deliver the widest temperature range of any standard elastomer — sealing reliably from -60°C to +230°C with excellent flexibility, weather resistance, and electrical insulation. Use them in food processing equipment, medical devices, automotive lighting, electronics enclosures, and any application where heat, cold, ozone, or steam would destroy ordinary rubber.

  • Material: VMQ, FVMQ, LSR, HCR / HTV
  • Hardness: 30 to 80 Shore A (customizable)
  • Temperature: -60°C to 230°C (special grades to 300°C)
  • Processing: Compression, Transfer, LSR Injection, Extrusion
  • Consistency: Batch-tested physical properties
  • MOQ: Flexible / Low MOQ Support
  • Lead Time: Prototype in 2-5 Days
  • Certifications: FDA, LFGB, ISO 9001, ROHS, REACH
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FDA 21 CFR 177.2600

Rubber Articles Intended for Repeated Use

LFGB 30&31

EU Food Contact Materials

USP Class VI / ISO 10993

Biocompatibility of Medical Devices

RoHS / REACH

Environmental Compliance

UL 94

Flammability of Plastic Materials

More

Built to Your Exact Spec

Custom Silicone O-ring Options

ImageProductTypeShort InfoAction
ISO 3601 Metric Silicone O-Rings ISO 3601 Metric Silicone O-Rings Standard & Size Metric silicone O-rings manufactured to ISO 3601 dimensions. Fits international equipment groove standards. View Details
ISO 6149 Metric Silicone O-Rings ISO 6149 Metric Silicone O-Rings Standard & Size Metric O-rings designed for hydraulic and pneumatic fluid power sealing applications under ISO 6149 standards. View Details
BS 1806 Silicone O-rings BS 1806 Silicone O-rings Standard & Size British Standard inch-size silicone O-rings. Common in UK and Commonwealth industrial equipment. View Details
DIN 3771 Silicone O-rings DIN 3771 Silicone O-rings Standard & Size German metric standard O-rings for hydraulic and pneumatic sealing in European machinery. View Details
Custom Molded Silicone O-rings Custom Molded Silicone O-rings Standard & Size Custom-shaped silicone O-rings molded to your exact drawing or sample. No standard size limitations. View Details
AS568 Silicone O-rings AS568 Silicone O-rings Standard & Size Inch-size silicone O-rings that follow the AS568 standard. Widely used in North American machinery and hydraulic systems. View Details
AN6227 Silicone O-rings AN6227 Silicone O-rings Standard & Size Aerospace-standard O-rings with small cross-section. Used in aviation and military-grade sealing. View Details
AN6230 Silicone O-rings AN6230 Silicone O-rings Standard & Size Aerospace-standard O-rings specified under AN6230 for aviation and military-grade sealing. View Details
JIS B2401 Silicone O-Ring JIS B2401 Silicone O-Ring Standard & Size Japanese industrial standard O-rings commonly used in Asian-manufactured machinery and automotive equipment. View Details
FDA Food Grade Silicone O-Rings FDA Food Grade Silicone O-Rings Grade Food-safe silicone O-rings compliant with FDA regulations. Safe for repeated food contact. View Details
Industrial Grade Silicone O-ring Industrial Grade Silicone O-ring Grade General-purpose silicone O-rings for industrial sealing. Cost-effective with reliable performance. View Details
Medical Grade Silicone O-ring Medical Grade Silicone O-ring Grade Biocompatible silicone O-rings for medical devices. Passes USP Class VI and supports sterilization. View Details
Oil-Resistant / Fuel-Resistant Silicone O-Rings Oil-Resistant / Fuel-Resistant Silicone O-Rings Special Function Modified silicone O-rings that resist swelling in oils, fuels and petroleum-based fluids. View Details
Metal Detectable Silicone O-Rings Metal Detectable Silicone O-Rings Special Function Food-safe silicone O-rings with metal-detectable additives. Protects production lines from contamination. View Details
High Temperature / Heat Resistant Silicone O-Rings High Temperature / Heat Resistant Silicone O-Rings Special Function Silicone O-rings that stay flexible at temperatures above 200°C. For ovens, engines and furnaces. View Details
VMQ Silicone O-Rings VMQ Silicone O-Rings Materials Heat and cold-resistant silicone O-rings for food, medical, automotive, and industrial applications. View Details
Fiberglass Reinforced Silicone O-rings Fiberglass Reinforced Silicone O-rings Materials High-strength silicone O-rings reinforced with fiberglass fabric. Withstands extreme heat and pressure. View Details
HCR / HTV / Solid Silicone Rubber O-rings HCR / HTV / Solid Silicone Rubber O-rings Materials Durable solid silicone rubber O-rings made by compression molding. The standard choice for general sealing. View Details
Liquid Silicone Rubber (LSR) O-rings Liquid Silicone Rubber (LSR) O-rings Materials Injection-molded liquid silicone rubber O-rings with tight tolerances and clean surfaces. Ideal for high-volume production. View Details
Platinum Cured Silicone O-rings Platinum Cured Silicone O-rings Materials Ultra-clean silicone O-rings cured with platinum catalyst. Lower extractables for food and medical use. View Details
Fluorosilicone (FVMQ) O-rings Fluorosilicone (FVMQ) O-rings Materials Fuel and oil-resistant silicone O-rings for aerospace, automotive and chemical applications. View Details
Transparent / Clear Silicone O-rings Transparent / Clear Silicone O-rings Color See-through silicone O-rings for visual inspection and clean-looking medical or food equipment. View Details
Black / White Silicone O-Rings Black / White Silicone O-Rings Color Standard black and white silicone O-rings. The most common colors for industrial and food-grade applications. View Details
Pantone Colors Silicone O-rings Pantone Colors Silicone O-rings Color Silicone O-rings in any Pantone color for branding, color-coding or aesthetic requirements. View Details
Custom Colors Silicone O-rings Custom Colors Silicone O-rings Color Silicone O-rings matched to your exact color sample or specification. View Details

VMQ vs Other Elastomers: How Silicone Compares

At ZSR Silicone Parts, VMQ is our core material. But we know buyers also consider NBR, EPDM, FKM, and other rubbers. The table below shows where VMQ wins and where it does not.

Feature

VMQ (Silicone)

NBR (Nitrile)

EPDM

FKM (Viton)

Temperature Range

-60°C to +230°C

-40°C to +120°C

-50°C to +150°C

-20°C to +250°C

Low-Temp Flexibility

Excellent

Poor

Good

Poor

Heat Resistance

Excellent

Poor

Good

Excellent

Oil Resistance

Poor

Excellent

Poor

Excellent

Fuel Resistance

Poor

Good

Poor

Excellent

Weather / Ozone / UV

Excellent

Poor

Excellent

Excellent

Water Resistance

Excellent

Good

Excellent

Good

Steam Resistance

Excellent

Poor

Excellent

Good

Tensile Strength

Low to Moderate

High

Moderate

Moderate

Tear Strength

Moderate

High

Moderate

Moderate

Compression Set

Good

Good

Good

Good

Cost

Medium

Low

Low

High

Best For

Heat, cold, weather, food, medical

Oil, fuel, general industrial

Water, steam, outdoor

Oil, fuel, extreme heat

ZSR's Simple Rule:
  • If your seal needs wide temperature range (especially below -40°C or above 150°C), VMQ is the answer.
  • If your seal needs oil or fuel resistance and never sees temperatures below -20°C, FKM or NBR is better.
  • If your seal needs both oil resistance and low temperature, FVMQ (fluorosilicone) bridges the gap.

At ZSR, we produce VMQ, FVMQ, and can source NBR, EPDM, and FKM if your project needs a non-silicone option. But for pure silicone performance, VMQ is the foundation.

VMQ Material Properties at ZSR

The table below shows the typical properties of ZSR's standard VMQ silicone O-rings. These values apply to our industrial-grade compound. Food-grade and medical-grade compounds may have slightly different values due to purer ingredients.

PropertyTypical ValueNotes
Hardness10 – 90 Shore AMost O-rings use 40 – 70 Shore A
Temperature Range-60°C to +230°C (continuous)Short-term peaks to +250°C
Tensile Strength5 – 9 MPaSufficient for static and light dynamic sealing
Elongation at Break200% – 800%Very flexible, especially at low hardness
Tear Strength15 – 45 kN/mGood for standard seals; reinforced grades available
Compression Set10% – 35%Good recovery after pressure release
Density1.10 – 1.25 g/cm³Lightweight compared to most rubbers
Volume Resistivity10¹⁴ – 10¹⁶ Ω·cmExcellent electrical insulator
Dielectric Strength20 – 30 kV/mmGood for electrical insulation applications
Color OptionsBlack, white, red, blue, transparent, custom PantoneFood-grade and medical-grade colors available
Standard Sizes at ZSR:
Tolerance Standards:

When to Choose VMQ Silicone O-Rings

VMQ is not the right material for every job. At ZSR, we help customers choose by asking what the seal must do.

Choose VMQ When:
  • Your equipment operates from -60°C to +230°C
  • You need excellent flexibility at low temperatures
  • Your seal is exposed to ozone, UV, or weather
  • Your application involves steam, hot water, or moisture
  • You need electrical insulation
  • You need food-grade or medical-grade purity
  • Your seal is static (not moving or rubbing)
  • You want a long service life in heat or cold
Do Not Choose VMQ When:
  • Your seal touches fuel, oil, or hydrocarbon solvents regularly (choose FVMQ or FKM instead)
  • Your seal is in a high-wear dynamic application with metal rubbing (VMQ has lower tear strength than NBR or polyurethane)
  • You need the absolute highest tensile strength (VMQ is weaker than NBR or natural rubber)
  • Your seal must survive strong acids or strong bases (VMQ degrades in concentrated acids and caustics)
Typical Applications for ZSR VMQ O-Rings:
  • Coffee machines and water dispensers
  • Medical devices and diagnostic equipment
  • Automotive lighting and sensor seals
  • Electronics enclosures and cable glands
  • Food processing and packaging equipment
  • Industrial ovens and heating equipment
  • Outdoor electrical boxes and solar inverters
  • Aerospace cabin pressure and avionics seals

What Is VMQ Silicone?

VMQ stands for Vinyl Methyl Silicone. It is the technical name for the most common type of silicone rubber used in O-rings and seals. The letters tell you about its

chemical structure:

  • V = Vinyl groups (added for cross-linking and strength)
  • M = Methyl groups (the basic silicone building block)
  • Q = Silicone (from the chemical symbol Si, but written as Q in rubber classification codes)

At ZSR Silicone Parts, when we say "silicone rubber," we almost always mean VMQ. It is the standard, general-purpose silicone that balances cost, performance, and availability.

What VMQ Is Made Of

VMQ is a synthetic elastomer. Its backbone is made of alternating silicon and oxygen atoms — a structure very different from carbon-based rubbers like NBR or EPDM. This silicon-oxygen backbone is what gives VMQ its unique properties:

  • It does not break down easily in heat.
  • It stays flexible far below freezing.
  • It resists ozone and UV light that destroy other rubbers.

Organic side groups (methyl and vinyl) are attached to the silicon atoms. These side groups control how the material cures, how strong it is, and how it behaves during processing.

How VMQ Is Made at ZSR

At ZSR, VMQ production follows these steps:

  • Compounding: We start with a raw VMQ base polymer. We add reinforcing fillers (usually fumed silica) to give the rubber strength, plus pigments for color and a curing agent.
  • Mixing: The ingredients are mixed on a mill or in a mixer until uniform.
  • Forming: For HCR/HTV, the compound is rolled into sheets and cut into preforms. For LSR, the two liquid parts are kept separate until injection.
  • Molding: The material is placed into a heated mold and pressed or injected. Heat activates the curing agent and the rubber becomes solid and elastic.
  • Post-Curing: Some grades receive a secondary oven bake to remove residual volatiles and stabilize the material.
Key Properties of VMQ
  • Temperature: -60°C to +230°C continuous. This is one of the widest temperature ranges of any rubber.
  • Flexibility: Stays soft and elastic even at very low temperatures. A VMQ O-ring at -60°C still seals better than an NBR O-ring at -20°C.
  • Heat Resistance: Does not harden or crack quickly at high temperatures. It outlasts NBR and EPDM in hot environments.
  • Weathering: Excellent resistance to ozone, UV light, and oxidation. VMQ O-rings last for years outdoors.
  • Chemical Resistance: Good against water, steam, dilute acids, and mild chemicals. Poor against hydrocarbon fuels and oils.
  • Electrical Properties: Excellent insulator. VMQ is widely used in electronics for sealing and insulation.
  • Purity: Can be made very pure using platinum curing. This makes VMQ ideal for food and medical applications.

VMQ is the standard silicone rubber that most people mean when they say "silicone." It is flexible, heat-resistant, cold-resistant, and weatherproof. It is not strong enough for heavy oil exposure or high-wear dynamic seals, but for static sealing in extreme temperatures and harsh environments, it is one of the best materials available. At ZSR, VMQ is the foundation of our O-ring product line, available in every grade from industrial to medical, in standard sizes and custom sizes, and in any color you need.