5-Pack Black FKM O-Ring Seals CS 2–5mm OD 5–115mm | Ouling

Ouling Black FKM Rubber O-Ring Seals – 5-Pack

Keep your plumbing, fuel systems, and mechanical assemblies leak-free with these premium FKM (Fluorocarbon) Rubber O-Rings from Ouling. Engineered for a wide range of industrial and DIY applications, these standard-sized sealing rings deliver outstanding chemical resistance, heat tolerance, and long-lasting compression set performance — making them a reliable choice for professional mechanics and home repair enthusiasts alike.

Made in Mainland China.

Product Highlights

• Pack of 5 – Great value for maintenance, repairs, or replacements
• Material: Premium FKM (Fluorocarbon) Rubber – excellent resistance to fuels, oils, hydraulic fluids, and high temperatures
• Available Cross-Section (CS) Thickness: 2mm / 2.8mm / 5mm
• Available Outer Diameter (OD): 5mm to 115mm – a broad range to cover most standard applications
• Color: Black
• Standard sizing – compatible with most machinery, fittings, and valves
• Suitable for use in fuel systems, hydraulic lines, plumbing, pneumatics, automotive applications, and more

Specifications

Why Choose FKM O-Rings?

FKM (also known as Viton®-type) rubber is one of the most versatile sealing materials available. Compared to standard NBR or silicone rings, FKM offers superior resistance to petroleum-based fuels and oils, solvents, and elevated temperatures — making it the go-to choice for demanding environments where standard rubber seals may degrade quickly.

Common Use Cases

• Automotive fuel injectors, carburetors, and fuel lines
• Hydraulic and pneumatic fittings
• Plumbing joints and pipe connections
• Industrial machinery and valve seals
• General mechanical repairs and maintenance

Looking for related tools and accessories? Check out our Universal Trimmer Replacement Parts and Quick Splice Wire Connectors for your next project.

Learn more: OSHA on personal protective equipment

Frequently Asked Questions

Q: What does FKM mean and why does it matter for O-rings?

A: FKM stands for Fluorocarbon rubber, commonly known by the trade name Viton®. It is a high-performance elastomer known for its outstanding resistance to fuels, oils, hydraulic fluids, chemicals, and high temperatures. FKM O-rings are ideal for demanding applications where standard rubber seals may break down prematurely.

Q: How do I choose the right O-ring size for my application?

A: You need to match two key dimensions — the Cross-Section (CS) thickness and the Outer Diameter (OD) of the O-ring to your fitting or groove. These Ouling FKM O-rings are available in CS thicknesses of 2mm, 2.8mm, and 5mm, with ODs ranging from 5mm to 115mm, covering most standard applications. Always measure the groove width and depth for the best fit.

Q: Are these O-rings suitable for fuel and oil systems?

A: Yes. FKM rubber has excellent resistance to petroleum-based fuels, engine oils, hydraulic fluids, and many solvents, making these O-rings well-suited for use in automotive fuel systems, hydraulic lines, and other fluid-handling equipment.

Q: How many O-rings come in each pack?

A: Each pack contains 5 O-rings of your selected size, giving you spares for future maintenance or for use across multiple fittings at once.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.