FVMQ 50A
Grade
50A = shore A 50
Use where an A60 seal is too stiff for the groove fill or the flange load is limited.
Values for the 50A 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 |
50AThis page 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 |
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 50A?
FVMQ 50A is FVMQ in the 50A grade — use where an A60 seal is too stiff for the groove fill or the flange load is limited. FVMQ 50A 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 (3.92×10⁻⁴ Msi). FVMQ 50A 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; 50A is available on request or by drawing note.
Limitations
- High mold shrinkage — 3.1%, 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 50A properties
Typical room-temperature values for FVMQ 50A; 15 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 50A 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 50A 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 (3.92×10⁻⁴ Msi).
Thermal8
FVMQ 50A 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 50A 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 50A 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 50A's machinability is poor (20/100, worse than 100% 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 50A
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 50A — frequently asked
What is FVMQ 50A used for?
FVMQ 50A 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 50A?
FVMQ 50A 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 50A easy to machine?
Not especially — machinability is rated poor (20/100, worse than 100% 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 50A 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 50A?
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 50A 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 50A?
FVMQ 50A 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.