30pcs EPDM Black O-Ring Seals | 2–3.5mm CS, 5–50mm OD

30-Pack EPDM Black O-Ring Seal Washers – Multiple Sizes Available

Keep your plumbing, machinery, and mechanical assemblies leak-free with these premium EPDM (Ethylene Propylene) Black O-Ring Seals. Each bag contains 30 pieces of precision-formed ring gaskets, available in cross-section sizes of 2 / 2.2 / 2.4 / 3.1 / 3.5 mm and outer diameters ranging from 5 mm to 50 mm — giving you the exact fit you need for a wide variety of applications.

Made in Mainland China.

Why Choose These EPDM O-Rings?

• High-Grade EPDM Rubber: Ethylene Propylene Diene Monomer rubber delivers excellent resistance to water, steam, heat, and many common chemicals — ideal for outdoor and industrial environments.
• Versatile Size Range: Cross sections of 2, 2.2, 2.4, 3.1, and 3.5 mm with outer diameters from 5 mm to 50 mm cover a broad spectrum of standard fittings and assemblies.
• Reliable Sealing Performance: The ring gasket shape compresses evenly to form a tight, durable seal that resists leaks under pressure.
• 30 Pieces Per Bag: Generous quantity ensures you have spares on hand for maintenance and repairs.
• Standard Specification: Conforms to standard dimensions for easy cross-referencing and drop-in replacement.
• Wide Application: Suitable for plumbing fittings, hydraulic systems, pneumatic connectors, automotive components, water pumps, garden hose fittings, and more.

Product Specifications

Common Applications

• Plumbing pipe fittings and connectors
• Hydraulic and pneumatic systems
• Automotive fuel and cooling line fittings
• Water pumps and garden hose fittings
• Industrial machinery sealing
• DIY home repair and maintenance

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Frequently Asked Questions

Q: What material are these O-ring seals made from, and why does it matter?

A: These O-rings are made from EPDM (Ethylene Propylene Diene Monomer) rubber, a high-performance synthetic elastomer known for its excellent resistance to heat, water, steam, and many chemicals. This makes EPDM O-rings ideal for plumbing, outdoor, and light industrial applications where exposure to the elements or fluids is a concern.

Q: How do I choose the right cross-section and outer diameter for my application?

A: You can measure the groove or fitting where the O-ring will sit. The cross-section (CS) refers to the thickness of the ring material (available in 2, 2.2, 2.4, 3.1, or 3.5 mm), while the outer diameter (OD) refers to the total outside measurement of the ring (5 mm to 50 mm). Match these measurements to your specific fitting for the best seal.

Q: How many O-rings are included in each bag?

A: Each bag contains 30 pieces of EPDM black O-ring seal washers, providing plenty of spares for maintenance, replacements, or multiple projects.

Q: Are these O-rings suitable for use with automotive fluids or fuel systems?

A: EPDM rubber is well-suited for water, steam, and many water-based fluids, but it is generally not recommended for petroleum-based fuels or oils. For fuel system applications, a nitrile (NBR) O-ring is typically a better choice. Please verify compatibility with your specific fluid before use.

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.