Confused by metric vs inch O ring kits? You’re not alone. With machinery sourced globally, choosing the wrong standard can cause costly sealing errors.
Choose the right sizing system to match your equipment origin and avoid downtime.
Read on to learn how to pick the right kit—and why many technicians stock both for maximum flexibility.
What’s the difference between metric and inch O ring kits?
Metric kits follow ISO/DIN sizing in millimeters. Inch kits follow SAE standards using imperial measurements.
If your equipment is built in the U.S. or Japan, inch kits are likely correct. For EU and many Asian machines, metric is the way to go.
| 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 |
Our O Ring Assortment Kits include both formats with labeled compartments and size charts.
Which industries typically use metric or inch kits?
Each industry tends to follow regional manufacturing norms.
| 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 |
In sectors with global fleets, teams often choose both kits to prevent downtime.
What if I use mixed machinery?
If you manage global equipment, you're not alone. One of our Middle Eastern clients uses both U.S. and German machines and keeps both kits on hand to ensure smooth repair workflows.
This dual-kit approach is common in logistics and industrial maintenance.
Where can I buy a complete metric or inch O ring kit?
We supply both kits made from high-grade NBR, packaged for ease of use:
- Inch Kit: 382 PCS in red case
- Metric Kit: 428 PCS in blue case
- Optional upgrade to Viton material for heat/chemical resistance
- Supports OEM/private label, low MOQ, and global shipping
For chemical or high-temperature needs, see our High Temp O Ring Kit with Viton/PTFE.
Need engine-specific solutions? Try our Fuel Injector O Ring Kit.
Conclusion
Choosing metric or inch kits depends on your equipment. With both on hand, you stay prepared across every repair.
Still Unsure? Let’s Help You Choose the Right Kit
📩 Email: [email protected]
📱 WhatsApp: +86 17622979498
Related topic
O Ring Kit: Why It’s a Smart Investment for Industrial Buyers? O-Ring Seal: The Ultimate Leak Prevention Guide (2025) How to Choose and Replace Hydraulic Seals (Step-by-Step)
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