Struggling to choose between a metric o ring kit and an inch-based set? Many technicians, distributors, and engineers face this exact challenge—especially when dealing with mixed machinery standards.
Choosing the wrong kit can lead to poor sealing, incorrect sizing, and wasted time. Here’s how to make the right decision based on your equipment and application needs.
The key difference between metric and inch o ring kits is their sizing standard. Metric kits follow ISO/DIN measurements (mm), while inch kits follow SAE (imperial) sizes. Choosing depends on where your equipment is manufactured and what standard it follows.
Knowing the difference helps avoid leakage, downtime, and fitting errors. Below, we explain the two kits we offer—and how to pick the one that works best for your industry.
What’s the difference between metric and inch o ring kits?
Metric o rings are measured in millimeters (mm) and are commonly used in equipment manufactured in Europe, Southeast Asia, and countries following ISO standards.
Inch o rings (also called imperial or SAE o rings) follow inch-based measurements and are standard in U.S.-made machinery, many Japanese models, and heavy equipment in North America.
Key Differences Table
| Feature | Metric O Ring Kit (428 PCS) | Inch O Ring Kit (382 PCS) |
|---|---|---|
| Measurement Standard | ISO / DIN (millimeter) | SAE / Inch (imperial) |
| No. of Sizes | 30 | 30 |
| Inner Diameter Range | 3.00 – 48.50 mm | 2.90 – 43.82 mm |
| Cross-Section Sizes | 1.50 / 2.00 / 2.50 / 3.00 mm | 1.78 / 2.62 / 3.53 / 5.33 mm |
| Ideal For | EU/Asia machinery, ISO equipment | U.S./Japan machines, SAE valves |
| Case Color | Blue | Red |
O-Ring Assortment
For high-heat or chemical environments, material matters more than sizing.
👉 Explore our Viton/PTFE High Temperature O Ring Kit →
Which industries typically use metric or inch kits?
Different industries and regions follow different standards. Here’s a quick overview to help you decide:
| Industry / Equipment | Most Common Kit Type | Why? |
|---|---|---|
| Automotive (Europe) | Metric Kit | EU-made vehicles follow ISO specs |
| Automotive (USA/Japan) | Inch Kit | SAE standard sizes dominate |
| Hydraulic Equipment | Both | Depends on machine origin |
| Industrial Maintenance | Both | Often mixed fleets = need both kits |
| OEM Manufacturing | Regional preference | Metric for EU, Inch for US |
If you maintain equipment from multiple regions, having both kits ensures you’re always prepared.
What if I use mixed machinery?
That’s exactly why we offer both kits—each covering 30 types and hundreds of pieces. Whether you’re sealing pumps, cylinders, injectors, or valves, our kits give you flexibility.
One of our Middle Eastern clients runs U.S. excavators and German processing machines on one site. They now stock both kits to avoid costly repair delays. That’s operational efficiency at its best.
Where can I buy a complete metric or inch o ring kit?
We manufacture both kits in-house with premium-grade NBR rubber (Viton optional), sorted by size and stored in labeled plastic boxes.
- Inch Kit (382 PCS): Red case
- Metric Kit (428 PCS): Blue case
- Available with OEM custom branding, private label, and bulk packaging
- Low MOQ, fast global shipping within 3–7 days
Need help choosing? Start with this resource:
👉 O Ring Kit
Final Thoughts on Choosing the Right O Ring Kit
Metric or inch—it’s not about which is better, it’s about which fits. By selecting the right o ring kit for your equipment standard, you save time, avoid seal failures, and complete every job with confidence.
Still Unsure? Let’s Help You Choose the Right Kit
We supply both metric and inch o ring kits—ready to ship, OEM customizable, and built for performance.
📩 Email: [email protected]
📱 WhatsApp: +86 17622979498
Tell us what equipment you maintain. We’ll recommend the perfect kit.
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