AS568-118 FS75 Fluorosilicone (FVMQ) 75 Duro O-Ring

Dimensions: 7/8"ID x 1-1/16"OD x 3/32"CS

The AS568-118 is a Fluorosilicone (FVMQ) 75 durometer blue O-Ring with a 7/8" inside diameter, a 1-1/16" outside diameter and a 3/32" cross-section. It is built for fuel systems and wide temperature swings, the spot where plain silicone gives up on fuel and standard rubber gives up on heat and cold. The O-Ring Store LLC stocks this size and ships most orders the same day.

Stop fuel leaks and seal parts that see both heat and cold with the AS568-118 Fluorosilicone O-Ring. This 75 durometer FVMQ seal handles jet fuel, gasoline and diesel while staying flexible from -75F all the way to +350F. That makes it a solid pick for aircraft fuel systems, engine parts and anywhere a regular O-Ring would swell, crack or take a set.

Operating Temperature

-75 to +350F (-59 to +177C)

Material and Performance Details

Fluorosilicone, also called FVMQ, mixes the wide temperature range of silicone with the fuel and oil resistance of a fluorocarbon. That combo is hard to beat when a part sees fuel one minute and a cold soak the next. The 75 Shore A durometer gives good squeeze and a firm seal without going brittle. The blue color makes it easy for a tech to spot the right material during a build or a service call. This line is built to the M25988/2 U.S. military standard for Fluorosilicone O-Rings, which sets tight rules for the material, the size and the fuel resistance, so you get the same part every time.

• Excellent resistance to: aviation fuels (JP-4, JP-5, JP-8), gasoline, diesel, jet fuel, engine and machine oils, di-ester lubricants, ozone, UV, sunlight and weathering
• Limited capability with: high-pressure steam, hot water over 250F, some esters
• Not compatible with: ketones such as MEK and acetone, glycol brake fluids, hydrazine, strong acids

Sizes and Measurements

• Dimensions: 7/8"ID x 1-1/16"OD x 3/32"CS
• Actual: 0.862"ID x 1.068"OD x 0.103"CS
• Metric: 21.89mm ID x 27.13mm OD x 2.62mm CS
• Part Number: FS75118
• AS568 Dash Number: 118
• Cross-references: AS568-118, Parker size 2-118

Applications and Use Cases

Fluorosilicone O-Rings earn their keep in aerospace and defense fuel systems. You will find them in aircraft fuel lines, pumps, injectors, filters and fittings, where the part has to shrug off jet fuel and still flex after a cold soak at altitude. They also work well in engine fuel systems, industrial fuel handling and any spot where both fuel exposure and a wide temperature range are in play. When plain silicone would swell in fuel and standard nitrile would crack in the cold, FVMQ keeps sealing.

Key Specifications

• Material: Fluorosilicone (FVMQ)
• Durometer: 75 Shore A
• Color: Blue
• Standard: M25988/2 (aerospace and military)
• Temperature Range: -75 to +350F (-59 to +177C)

Why Buy from The O-Ring Store LLC

The O-Ring Store LLC is an ISO 9001:2015 certified distributor with USA stock for fast delivery. Most in-stock items ship the same day. We handle custom sizes, and we can send full lot traceability and documentation when you need it. Every order gets checked through our Olypsys(R) scan-based quality system before it leaves the building. Fair pricing, real people and no runaround. We make getting O-Rings easy!

Frequently Asked Questions

Q: What temperature range does this Fluorosilicone O-Ring handle?
A: It seals from -75F to +350F (-59C to +177C), so it holds up in both cold soaks and hot fuel systems.

Q: Is Fluorosilicone good for fuel?
A: Yes. FVMQ resists gasoline, diesel and aviation fuels like JP-4, JP-5 and JP-8, which is why it is common in aircraft fuel systems.

Q: What size is the AS568-118?
A: It measures 7/8"ID x 1-1/16"OD x 3/32"CS, or 21.89mm ID x 2.62mm CS in metric. The AS568 dash number is 118.