Silicone O-Rings (VMQ) | Extreme Temperature & Food-Grade Seals

What is a Silicone O-ring?

Silicone (VMQ) O-rings are go-to extreme temperature o-rings with excellent low-temp flexibility and high-temp stability. Frequently used in food/medical equipment, clean packaging, and cold environments; not suitable for fuels, aromatics, or silicone oils.

Typical range: -60°C to +230°C (some higher), staying soft in cold while withstanding elevated bake/oven temperatures.

Composition & Properties

Silicone O-rings keep elasticity at low temp; for fuel/solvent resistance choose FKM/FFKM/PTFE instead.

• Hardness: 30–90 Shore A; common 50–70A balancing softness and support.
• Mechanical: very flexible but moderate wear/tear resistance—best for static or low-speed dynamic seals.
• Formulations: food/medical grades, transparent or custom colors; some high-temp/bake-stable types.

Temperature Range

• Continuous: about -60°C to +230°C; some grades up to +250°C.
• Low-temp: strong flexibility for cold storage and outdoor cold climates.
• Steam: not suited for high-temp steam—choose EPDM/FFKM for prolonged steam.

Chemical Compatibility

• Good for: air/dry gases, water (ambient), some food-contact media, mild acids/bases.
• Not for: fuels, aromatics, strong acids/bases, silicone oils/solvents, many organic solvents.
• Food/medical: FDA/USP-grade silicone O-rings available for hygienic use.

Advantages

• Extreme temp: low-temp softness + high-temp stability for cold or bake environments.
• Food/medical ready: food-grade/medical-grade options with low odor, customizable colors.
• Seal-friendly: good compression recovery for static seals; easy installation.
• Electrically insulating: useful for certain electrical enclosures (check media compatibility).

Applications

• Food processing, medical devices, clean packaging—use food/medical-grade silicone o-rings.
• Cold storage/low-temp equipment; high-temp oven/static seals.
• Electronics/electrical enclosures (verify chemical environment).
• Water/air static seals (ambient); avoid fuels, aromatics, silicone oils.

Size Coverage (AS568 / Metric)

• AS568 000–475 available in silicone; common 50–70A with batch labels.
• Metric/large/custom profiles available; compression/finish guidance for extreme temp seals.
• Food/medical grades on request; confirm certification/lead time.

Ordering & Traceability

• Mixed MOQ 1 across AS568/metric; batch photos/barcodes for traceability.
• Submit size tables to lock batches/lead times; color-coding available.
• Confirm media to avoid fuels/aromatics/silicone oils; alternatives provided if needed.

FAQs

• Silicone vs FKM: choose silicone for extreme temp/food; choose FKM/FFKM for fuels/solvents.
• Steam? Not recommended—use EPDM/FFKM for hot steam.
• Color/food-grade? Transparent/custom colors; food/medical certification available.
• Dynamic wear? Silicone has modest wear resistance; avoid high-speed dynamics—use FKM/HNBR instead.

Installation & Selection Tips

• Compression: static 15–25%, dynamic 10–20%; use food-grade lube to prevent tearing.
• Avoid fuels/aromatics/silicone oils—otherwise switch to FKM/PTFE.
• Storage: keep sealed, away from heat/ozone/UV; FIFO to maintain elasticity.