CS3mm O-Rings EPDM NBR VMQ FKM Rubber Seals Gasket OD9–54mm

CS3mm Multi-Material O-Rings – EPDM, NBR, VMQ, FKM Rubber Seals & Gaskets

Keep your systems leak-free with these precision-engineered CS3mm O-rings, available in a wide range of outer diameters (OD 9–54mm) and multiple high-performance rubber compounds. Whether you need chemical resistance, heat tolerance, or all-round durability, there's a material option perfectly suited to your application.

Material Options & Their Strengths

• EPDM (Green/Black) – Excellent resistance to weather, ozone, steam, and water-based fluids. Ideal for outdoor and plumbing applications.
• NBR – Nitrile (Black) – Superior resistance to oils, fuels, and hydraulic fluids. A go-to for automotive and industrial sealing.
• VMQ – Silicone (Red/White) – Outstanding temperature range performance; flexible and food-grade compatible for use in appliances and food-processing equipment.
• FKM – Fluorine/Viton (Green) – Premium resistance to aggressive chemicals, high temperatures, and fuels. The top choice for demanding industrial environments.

Key Features

• Cross-Section (CS): 3mm for a secure, consistent seal
• Outer Diameter (OD): 9mm to 54mm — wide size range for versatile fitment
• Shape: Standard ring/gasket profile for easy drop-in installation
• Material: High-quality rubber compounds — EPDM, NBR, VMQ, FKM
• Standard-sized: Compatible with common international sealing standards
• Available in multiple colors: Green, Black, Red, White — easy material identification at a glance

Typical Applications

• Plumbing fittings and valves
• Automotive engines and hydraulic systems
• Pneumatic equipment and compressors
• Food-processing and kitchen appliances (VMQ)
• Chemical processing and industrial machinery (FKM)
• HVAC and refrigeration systems

Made in Mainland China.

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Learn more: OSHA guidance on hand and power tools

Frequently Asked Questions

Q: What is the cross-section (CS) size of these O-rings, and what does it mean?

A: The cross-section (CS) of these O-rings is 3mm. This refers to the thickness (diameter) of the rubber cord that forms the ring. A 3mm CS ensures a robust, reliable seal across a broad range of standard grooves and fittings, making it one of the most commonly used sizes in industrial and household applications.

Q: Which material should I choose — EPDM, NBR, VMQ, or FKM?

A: Your choice depends on your application. Choose NBR (Nitrile) for oil and fuel resistance, EPDM for water, steam, and outdoor use, VMQ (Silicone) for wide temperature ranges and food-contact applications, and FKM (Fluorocarbon/Viton) for aggressive chemicals and extreme heat environments. The color coding also helps: Black (NBR/EPDM), Green (FKM/EPDM), Red or White (VMQ).

Q: Are these O-rings compatible with standard fittings and grooves?

A: Yes. These are standard-profile CS3mm O-rings with outer diameters ranging from 9mm to 54mm, designed to fit common international sealing grooves and fittings used in plumbing, automotive, pneumatic, and industrial systems.

Q: How many O-rings are included per order?

A: The quantity per order may vary depending on the size and material variant selected. Please refer to the specific variant listing or product options when placing your order for precise quantity information.

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.