Oil Seal by Size: How to Choose the Right Fit for Your Machinery?

Using the wrong size oil seal can lead to oil leaks, equipment damage, and costly downtime. Are you struggling to match oil seals to your machinery?

Choosing the right oil seal size ensures proper shaft protection, optimal sealing, and long-term equipment performance. Here’s how to get it right every time.

One size doesn’t fit all. From industrial pumps to automotive gearboxes, the correct oil seal size depends on your shaft, housing, and operating conditions. In this guide, I’ll help you decode dimensions and avoid mismatches.

What Are the Standard Oil Seal Size Parameters?

Oil seals are defined by three key dimensions: ID (inner diameter), OD (outer diameter), and Width/Thickness. These determine fit and sealing effectiveness.

Correct size selection prevents:

• Premature wear
• Oil leakage
• Misalignment and vibration

How to Choose Oil Seal by Size

As someone who’s worked with maintenance engineers and OEM clients for years, I’ve seen how one small error in sizing leads to massive failures. Here’s how I guide customers:

1. Understand the 3 Main Measurements

2. Metric vs Inch Systems

Oil seals are available in both measurement systems.

• Metric (e.g., 30×47×7 mm) – common in Asia, EU
• Inch (e.g., 1.125” × 1.875” × 0.312”) – mostly US equipment
  Need help converting? Try our Cross Reference Chart

3. Use a Reference or Code

Many oil seals have part numbers like “TC 30×47×7” — which means:

• TC = double lip with spring
• 30 = shaft size
• 47 = housing bore
• 7 = width
  ➡️ See more types here: TC Oil Seal Structure & Uses

How to Match the Right Oil Seal to Your Application?

Different industries require different types and fits. Here’s how I approach it:

Need custom sizing? We provide OEM-sized oil seals with no MOQ.

How to Measure If the Old Seal Is Damaged?

Even if the original oil seal is worn or torn, you can still determine its size:

• Measure the shaft directly (for ID)
• Use the housing bore (for OD)
• Check groove depth or leftover width
• Compare with standard oil seal types

Don’t guess — a 1 mm mistake can ruin the seal. Contact us if unsure, we’ll size-match it for you in 12 hours or less.

Conclusion

Getting the oil seal size right is the key to longer service life and zero leakage. Measure precisely, cross-check codes, and choose quality seals.

Call to action

Not sure which size fits your application? Let us help you find the perfect oil seal — fast, precise, and customizable.

• Email: [email protected]
• WhatsApp: +86 17622979498
  Send us your shaft or bore size — we’ll send back exact match options within 12 hours.

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