Finding the right sealing solution can be challenging, especially when precision is critical. Metric buna o rings, like the 18.8 x 1.9mm size, are widely used in hydraulic, pneumatic, and industrial applications. But how do you choose the right one? This guide covers everything you need to know.
Metric buna o rings offer excellent oil resistance, durability, and flexibility, making them a top choice for sealing applications in automotive, machinery, and hydraulic systems.
What Are Metric Buna O Rings?
Metric buna o rings are sealing rings made from nitrile rubber (NBR) with dimensions measured in millimeters instead of inches. They provide effective sealing solutions in applications where standard inch-size o rings do not fit.
Metric buna o rings are commonly used in hydraulic and pneumatic systems, automotive components, and industrial machinery, offering reliable performance in environments exposed to oils, fuels, and certain chemicals.
Not sure if a Buna O-Ring is the right choice? Learn everything about it in our
Buna O-Rings Complete Guide.
What Are the Common Sizes of Metric Buna O Rings?
Metric buna o rings come in various standard sizes. Here are some commonly used sizes, including 18.8 x 1.9mm, which is popular in hydraulic applications:
| Inner Diameter (mm) | Cross-Section (mm) | Common Use Cases |
|---|---|---|
| 10.0 | 2.0 | Pumps, valves |
| 15.5 | 2.5 | Hydraulic systems |
| 18.8 | 1.9 | Pneumatic seals |
| 22.4 | 3.1 | Automotive applications |
| 30.0 | 4.0 | Industrial machinery |
For custom sizes, suppliers like Hengoseal provide tailored solutions to meet specific requirements.
Are Metric Buna O Rings Compatible with Hydraulic Systems?
Yes, metric buna o rings are commonly used in hydraulic systems due to their excellent resistance to hydraulic oils and wear. They provide effective sealing for:
- Hydraulic cylinders to prevent fluid leakage.
- Pumps and valves to maintain system pressure.
- Pneumatic actuators for efficient air or fluid flow control.
However, if your system operates at high temperatures or with aggressive chemicals, alternative materials like Viton or EPDM o rings may be a better choice.
How Do I Measure a Metric O Ring Correctly?
To ensure a proper fit, follow these steps when measuring a metric buna o ring:
- Measure the inner diameter (ID) – Use a caliper to measure the distance across the inside of the o ring.
- Measure the cross-section (CS) – Determine the thickness by measuring the ring’s cross-section.
- Confirm the outer diameter (OD) – The OD is calculated by adding twice the CS to the ID (OD = ID + 2 × CS).
- Compare with size charts – Match your measurements with standard metric o ring size charts for the best fit.
Using the right size ensures leak-proof performance and extends the o ring’s lifespan.
How to Select the Best Metric Buna O Ring?
Choosing the right metric buna o ring depends on several factors:
| Selection Factor | Why It Matters |
|---|---|
| Material | Ensure it matches the application’s fluid compatibility. |
| Size | A precise fit is crucial for optimal sealing performance. |
| Temperature Range | Standard buna o rings withstand -40°C to 120°C. |
| Pressure Rating | Higher durometer (hardness) may be needed for high-pressure systems. |
| Application Environment | Consider exposure to oil, fuel, or chemicals. |
If you are unsure, consult a reliable supplier like Hengoseal to get expert recommendations.
Where Can I Buy High-Quality Metric Buna O Rings?
For high-quality metric buna o rings, Hengoseal is your trusted partner. We offer:
- Customizable o rings to fit specific industrial applications.
- Competitive factory pricing with low minimum order quantities.
- Fast global shipping for urgent sealing solutions.
Contact us today:
📧 Email: [email protected]
📞 WhatsApp: +86 17622979498
🌐 Visit: hengoseal.com
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