NBR O-Ring
Reliable Nitrile Rubber O-Rings from a China Custom Manufacturer
Product Overview
NBR O-rings, also known as Nitrile O-rings or Buna-N O-rings, are the most commonly used sealing components in industrial systems that handle oils, fuels, and lubricants. At Xiamen Jinshun Sealing Technology Co., Ltd., we manufacture and export standard and custom NBR O-rings for global OEMs, distributors, and wholesale partners.
With in-house production in China, strict material control, and flexible customization, we supply millions of NBR O-rings every year to automotive, hydraulic, plumbing, and industrial equipment manufacturers worldwide.
What Is an NBR O-Ring?
An NBR O-ring is a circular elastomer seal made from Nitrile Butadiene Rubber, a synthetic material created by combining acrylonitrile (ACN) and butadiene. This structure gives NBR excellent resistance to petroleum-based oils, fuels, and greases while keeping material costs low.
Because of this balance of performance and price, NBR O-rings are estimated to account for 40–60% of all rubber O-ring usage globally, especially in automotive and hydraulic applications.
Why Choose NBR O-Rings?
NBR remains the industry standard because it delivers consistent sealing performance in demanding environments without unnecessary cost.
Key reasons engineers choose NBR O-rings:
- Strong resistance to oils and fuels
- Good mechanical strength and wear resistance
- Stable performance from –40°C to +120°C
- Easy to mold into standard and custom sizes
- Cost-effective for mass production
As a custom NBR O-ring manufacturer, Jinshun can fine-tune hardness, formulation, and dimensions to match your exact application.
NBR O-Ring Material Specifications
| Item | Specification |
|---|---|
| Material | NBR / Nitrile / Buna-N / Perbunan |
| Temperature Range | –40°C to +120°C (–40°F to +248°F) |
| Standard Hardness | Shore A 70 |
| Available Hardness | Shore A 50 / 60 / 70 / 80 / 90 |
| Color | Black (standard), custom colors available |
| Cross-Section Shape | Round |
| Cross-Section Width | 0.5 – 20 mm (0.020 – 0.787 in) |
| Inside Diameter | 0.7 – 2965 mm (0.028 – 116.7 in) |
| Standards | AS568, ISO 3601, DIN 3771, BS 1806, JIS B 2401 |
| Shelf Life | 5–7 years |
| Price Level | Low |
Resistance Characteristics of NBR O-Rings
NBR O-rings are designed for oil-rich environments. Below is a practical overview of their resistance performance.
| Medium / Condition | Resistance Level |
|---|---|
| Petroleum Oils & Fuels | Excellent |
| Abrasion | Good |
| Compression Set | Good |
| Water | Good |
| Dilute Acids & Alkalis | Fair |
| Steam | Fair |
| Weather & UV | Fair |
| Ozone | Poor |
| Flame | Poor |
Standard NBR O-Ring Material Data (Shore A 70)
Our standard NBR compound complies with ASTM D2000 M2BG714 and is widely used for automotive and hydraulic sealing.
Physical Properties
| Property | Test Method | Result |
|---|---|---|
| Hardness | ASTM D2240 | 72 Shore A |
| Tensile Strength | ASTM D412 | 19 MPa |
| Elongation at Break | ASTM D412 | 300% |
| Specific Gravity | ASTM D792 | 1.22 |
Heat & Compression Performance
| Test Condition | Result |
|---|---|
| Heat Aging (70h @ 100°C) | Hardness change +5 |
| Compression Set (22h @ 100°C) | 18% |
| Low Temp Flexibility (–40°C) | Pass |
These are typical values. Actual performance may vary depending on operating pressure, fluid type, and exposure time. Sample testing is recommended for critical applications.
Advantages and Limitations of NBR O-Rings
Advantages
- Excellent oil and fuel resistance
- Reliable sealing for static and low-speed dynamic use
- Strong abrasion and tear resistance
- Easy to customize for OEM projects
- One of the most economical elastomer materials
Limitations
- Poor resistance to ozone, UV, and weathering
- Not suitable for brake fluids (DOT 3/4)
- Limited high-temperature resistance above +120°C
For harsh chemical or high-temperature environments, materials such as FKM (Viton®), HNBR, or EPDM may be more suitable.
Typical Applications of NBR O-Rings
NBR O-rings are widely used in systems where oil, fuel, or grease sealing is critical:
- Automotive fuel systems and engines
- Hydraulic pumps, cylinders, and valves
- Industrial machinery and gearboxes
- Oil tanks and fluid reservoirs
- Plumbing and water treatment equipment
Their proven reliability makes them a first-choice seal for both OEM production and aftermarket replacement.
Why Work with Jinshun as Your Custom NBR O-Ring Manufacturer?
- In-house molding and compounding in China
- Metric, inch, and non-standard sizes available
- Low MOQ for custom projects
- Stable quality for long-term supply programs
- Export experience with global brands and distributors
We support ODM and OEM customers from design review to mass production.
FAQs
Q1: Are NBR O-rings and Buna-N O-rings the same?
Yes. Buna-N is simply another name for NBR.
Q2: Can you produce custom NBR O-ring sizes?
Yes. We manufacture standard and fully custom dimensions.
Q3: What hardness is most commonly used?
Shore A 70 is the industry standard, but other hardness levels are available.
Q4: Are NBR O-rings suitable for water?
Yes, for most water applications up to 100°C.
Looking for a reliable custom NBR O-ring manufacturer in China?
👉 Visit https://www.jinshunsealing.com/
👉 Send us your drawings, standards, or application details
👉 Get fast technical support and competitive factory pricing
Xiamen Jinshun Sealing Technology - your long-term partner for quality rubber sealing solutions.
