FVMQ LSR-F
Grade
LSR-F = liquid fluorosilicone rubber
Use for high-volume automated injection molding of small fuel/oil seals and micro-parts.
Values for the LSR-F condition
Other FVMQ grades and fills
FVMQ is listed in 10 conditions; see the grade overview at FVMQ.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Carbon/silver-filled conductive & EMI-shielding fluorosilicone | Pick for EMI gaskets on fuel-wetted or oil-exposed enclosures needing both shielding and sealing. | — | 4 | 150 | 65 Shore A |
Shore A 40 | Pick for low-compression-force gaskets, diaphragms and thin membranes needing high extensibility. | — | 7 | 350 | 40 Shore A |
Flame-retardant fluorosilicone | Choose where a UL 94 V-0 rating or low flame spread is required in addition to fuel resistance. | — | 7 | 200 | 65 Shore A |
Shore A 50 | Use where an A60 seal is too stiff for the groove fill or the flange load is limited. | — | 8 | 300 | 10 Shore D |
Low-temperature fluorosilicone | Specify for high-altitude / arctic fuel seals that must stay flexible below -60 °C. | — | 8 | 260 | 60 Shore A |
LSR-FThis page Liquid fluorosilicone rubber | Use for high-volume automated injection molding of small fuel/oil seals and micro-parts. | — | 8 | 300 | 12 Shore D |
60ADefault Shore A 60 | Default aerospace/industrial fuel-seal compound: best balance of sealing force, elongation and compression set. | — | 9 | 250 | 15 Shore D |
Shore A 70 | The usual hardness for fuel-system O-rings with moderate pressure and extrusion-gap risk. | — | 9 | 200 | 23 Shore D |
Shore A 80 | Choose for higher pressures / larger extrusion gaps where seal stiffness matters more than elongation. | — | 10 | 150 | 30 Shore D |
High-tear / high-strength fluorosilicone | For thin diaphragms, boots and parts demolded over undercuts where tear propagation is the failure mode. | — | 11 | 320 | 12 Shore D |
What is FVMQ LSR-F?
FVMQ LSR-F is FVMQ in the LSR-F grade — use for high-volume automated injection molding of small fuel/oil seals and micro-parts. FVMQ LSR-F has a tensile strength of 8 MPa (1.09 ksi), stronger than 50% of silicone grades. Elongation at break is 300% and the elastic modulus is 0 GPa (4.79×10⁻⁴ Msi). FVMQ LSR-F has a density of 1.45 g/cm³ (0.0524 lb/in³), heavier than 100% of silicone grades. Its glass-transition temperature is -70°C (-94 °F). 60A is the default condition FabDigit quotes; LSR-F is available on request or by drawing note.
Limitations
- High mold shrinkage — 3.2%, worse than 150% of silicone grades
- Heavy — 1.45 g/cm³ (0.0524 lb/in³), worse than 100% of silicone grades
- High embodied carbon — 11 kg CO₂/kg, worse than 100% of silicone grades
- Absorbs moisture — dry before molding — 0.4%, worse than 100% of silicone grades
FVMQ LSR-F properties
Typical room-temperature values for FVMQ LSR-F; 16 are specific to this condition. Other listed values are FVMQ reference data and may not represent this condition. Bars are the position among silicone grades.
Physical3
FVMQ LSR-F has a density of 1.45 g/cm³ (0.0524 lb/in³), heavier than 100% of silicone grades. Its glass-transition temperature is -70°C (-94 °F).
Mechanical8
FVMQ LSR-F has a tensile strength of 8 MPa (1.09 ksi), stronger than 50% of silicone grades. Elongation at break is 300% and the elastic modulus is 0 GPa (4.79×10⁻⁴ Msi).
Thermal8
FVMQ LSR-F is rated for continuous service to 200°C (392 °F). It conducts heat at 0.21 W/m·K (0.121 BTU/hr·ft·°F), better than 50% of silicone grades. Thermal expansion is 230 µm/m·K (127.8 µin/in·°F).
Electrical6
FVMQ LSR-F is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 75% of silicone grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of FVMQ LSR-F takes about 190 MJ of energy and emits 11 kg of CO₂ — more than 100% of silicone grades. Typical recycled content is 0%.
Manufacturability4
FVMQ LSR-F's machinability is poor (25/100, better than 50% of silicone grades); formability excellent (88/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with FVMQ LSR-F
Is FVMQ easy to machine?
Not machined in the usual sense — die-cut, waterjet or cryogenically deflashed; cured stock grinds/tears easily, so use sharp dies and freeze-flash removal.
Can FVMQ be welded?
Not weldable; join by re-molding, Pt-cured self-bonding adhesives or silicone RTV, with plasma/primer treatment for bonding to metals.
Can FVMQ be formed, bent or molded?
Compression/transfer mold peroxide compounds at 160–180 °C, or injection-mold liquid Pt-cured F-LSR at 150–200 °C; a 200 °C/4 h post-cure is essential to strip volatiles and hit compression-set targets, and 2.5–4 % shrinkage must be allowed.
What surface finishes work on FVMQ?
Surfaces can be plasma- or primer-treated for bonding/printing; fabric or PTFE-film lamination is used for low-friction diaphragms; no plating or painting.
FVMQ 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| methylvinylsiloxane comonomercure-site units | 0.05 – 0.6 | 0.2 |
| fumed silica (reinforcing filler)with silane/silazane surface treatment | 20 – 35 | 28 |
| iron oxide / rare-earth heat stabilizer | 0.5 – 3 | 1.5 |
| peroxide or Pt cure system2,5-dimethyl-2,5-di(t-butylperoxy)hexane, or Pt/vinyl-hydride for LSR | 0.3 – 1.5 | 0.8 |
| poly(methyl-3,3,3-trifluoropropyl)siloxafluorinated siloxane base polymer, ~1 CF3 per repeat unit | ≥ 55 (balance) | — |
FVMQ LSR-F — frequently asked
What is FVMQ LSR-F used for?
FVMQ LSR-F is typically used for aircraft fuel seals, fuel-resistant gaskets and aerospace O-rings. In short: fuel-resistant silicone; wider temperature range than FKM; higher cost than VMQ.
What is the tensile strength of FVMQ LSR-F?
FVMQ LSR-F has a typical tensile strength of 8 MPa (1.09 ksi) — stronger than 50% of silicone grades. Strength varies by condition: see the 10 listed tempers.
Is FVMQ LSR-F easy to machine?
Not especially — machinability is rated poor (25/100, better than 50% of silicone grades). Not machined in the usual sense — die-cut, waterjet or cryogenically deflashed; cured stock grinds/tears easily, so use sharp dies and freeze-flash removal.
Can FVMQ LSR-F be welded?
Not weldable; join by re-molding, Pt-cured self-bonding adhesives or silicone RTV, with plasma/primer treatment for bonding to metals.
What surface finishes work on FVMQ LSR-F?
Surfaces can be plasma- or primer-treated for bonding/printing; fabric or PTFE-film lamination is used for low-friction diaphragms; no plating or painting.
Can FVMQ LSR-F be formed, bent or molded?
Compression/transfer mold peroxide compounds at 160–180 °C, or injection-mold liquid Pt-cured F-LSR at 150–200 °C; a 200 °C/4 h post-cure is essential to strip volatiles and hit compression-set targets, and 2.5–4 % shrinkage must be allowed.
What is the maximum service temperature of FVMQ LSR-F?
FVMQ LSR-F is rated for continuous use to about 200°C (392 °F), and briefly to 230°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D2000 (FK class fluorosilicone line callouts) — ASTM International (2021)
- AMS 3325 / AMS 3327 Fluorosilicone Rubber, fuel resistant — SAE International (2019)
- MIL-DTL-25988 Rubber, Fluorosilicone Elastomer, Oil- and Fuel-Resistant — US DoD (2015)
- Fluorosilicone rubber (FSR) compound datasheets — Shin-Etsu / Momentive / Dow (2023)
- Engineered Materials Handbook Vol. 2: Engineering Plastics & Elastomers — ASM International (1988)
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.