30-Pack NBR O-Rings CS 3.55mm ID 36.5–42.3mm Rubber Seal Gaskets

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30-Pack NBR Rubber O-Ring Seals — Industrial Grade Gaskets

Keep your hydraulic, pneumatic, plumbing, and mechanical systems leak-free with this convenient 30-piece set of Nitrile Butadiene Rubber (NBR) O-rings. With a cross-section of 3.55 mm and inner diameters ranging from 36.5 mm to 42.3 mm, these standard-dimension ring gaskets deliver a reliable, durable seal across a wide range of industrial and DIY applications.

Key Features

Premium NBR Material: Nitrile rubber offers excellent resistance to oils, fuels, and hydraulic fluids, making these O-rings ideal for demanding industrial environments.
Multiple Inner Diameter Options: Available in ID sizes of 36.5 mm, 37.5 mm, 38.7 mm, 40 mm, 41.2 mm, and 42.3 mm — perfect for matching your specific application.
Consistent Cross-Section: Uniform CS 3.55 mm cross-section ensures a snug, dependable fit in standard grooves.
Pack of 30: Generous quantity keeps your tool kit stocked for maintenance, repairs, and replacements.
Wide Application Range: Suitable for pumps, valves, fittings, compressors, hydraulic cylinders, and more.
Standard Dimensions: Manufactured to standard O-ring specifications for broad compatibility.

Specifications

Material	NBR (Nitrile Butadiene Rubber)
Cross-Section (CS)	3.55 mm
Inner Diameter (ID)	36.5 / 37.5 / 38.7 / 40 / 41.2 / 42.3 mm
Shape	Ring Gasket
Standard	Standard
Quantity	30 pieces per lot
Country of Origin	Made in Mainland China

What Are NBR O-Rings Used For?

NBR O-rings are among the most versatile sealing solutions in industry and home repair. They create a compression seal between mating surfaces, preventing fluid or gas leakage in assemblies such as faucets, hydraulic systems, pneumatic tools, automotive components, and industrial machinery. Having a selection of sizes on hand ensures you're ready for routine maintenance or unexpected repairs.

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Frequently Asked Questions

Q: What does NBR stand for and why is it a good material for O-rings?

A: NBR stands for Nitrile Butadiene Rubber. It is widely used for O-ring seals because of its strong resistance to petroleum-based oils, fuels, hydraulic fluids, and many industrial chemicals. This makes NBR O-rings a reliable choice for automotive, hydraulic, and general industrial sealing applications.

Q: How do I choose the correct inner diameter for my application?

A: Measure the groove or shaft your O-ring will seat in. The inner diameter (ID) of the O-ring should match the diameter of the groove or the bore it seals. This set includes IDs of 36.5, 37.5, 38.7, 40, 41.2, and 42.3 mm, all with a 3.55 mm cross-section, giving you flexibility across similar-sized fittings and assemblies.

Q: Are these O-rings compatible with water and plumbing systems?

A: Yes. NBR rubber is suitable for use in water, oil, and many common fluid systems, making these gasket rings a practical choice for plumbing fittings, valve maintenance, and general household or workshop repairs.

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

A: Each lot contains 30 pieces of NBR rubber O-ring seal gaskets, providing an ample supply for multiple maintenance tasks or repair jobs.

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.

We prioritize quality in selecting the materials for our items, choosing premium fabrics and finishings that ensure durability, comfort, and timeless appeal.

We strive to process and ship all orders in a timely manner, working diligently to ensure that your items are on their way to you as soon as possible.