NBR 70 O-Rings: The Reliable All-Round Sealing Solution

NBR 70 nitrile O-ring showing suitability for oil, fuel and general sealing applications, with icons and Seal With Selo branding.

When it comes to sealing solutions, one material stands above the rest for versatility, availability and performance — NBR 70 O-rings.

Used across automotive, industrial and general engineering applications, NBR 70 is often the go-to choice for everyday sealing tasks.

But what makes it so widely used?


What Are NBR 70 O-Rings?

NBR stands for nitrile rubber, a synthetic elastomer known for its excellent resistance to oils and fuels.

The number 70 refers to the Shore A hardness, which represents a balanced level of:

  • flexibility
  • durability
  • sealing performance

This makes NBR 70 O-rings suitable for a huge range of applications.


Why NBR 70 O-Rings Are So Widely Used

A True All-Rounder

NBR 70 offers a combination of properties that make it ideal for general-purpose sealing:

  • good flexibility for easy installation
  • strong sealing performance under moderate pressure
  • reliable performance across a wide temperature range

It’s often the default choice when no extreme conditions are present.


Excellent Oil & Fuel Resistance

One of the biggest advantages of nitrile is its compatibility with:

  • engine oils
  • gearbox oils
  • hydraulic fluids
  • diesel and petrol

This is why NBR 70 O-rings are commonly used in automotive and mechanical systems.


Wide Temperature Range

NBR 70 typically operates between:

−20°C to +100°C

This covers the majority of everyday applications, from machinery to vehicle systems.


Cost-Effective Without Compromise

Compared to more specialist materials like FKM (Viton®), NBR offers:

  • strong performance
  • wide availability
  • lower cost

This makes it a practical solution for both trade and individual buyers.


Common Uses for NBR 70 O-Rings

Automotive Applications

NBR 70 O-rings are widely used in:

  • engines
  • gearboxes
  • fuel systems
  • oil sealing points

Hydraulic & Pneumatic Systems

Used in:

  • hydraulic fittings
  • pumps
  • air systems

where moderate pressure sealing is required.


General Engineering

Perfect for:

  • machinery
  • maintenance repairs
  • everyday sealing jobs

Why Quality Matters with NBR 70 O-Rings

Not all O-rings are created equal.

A high-quality NBR 70 O-ring should offer:

  • consistent material composition
  • accurate sizing
  • good elasticity and recovery
  • resistance to cracking or premature wear

Poor-quality O-rings can lead to:

  • leaks
  • system failure
  • unnecessary downtime

That’s why sourcing from a reliable supplier is key.


NBR 70 O-Rings at Seal With Selo

At Seal With Selo, we focus on supplying quality NBR 70 O-rings you can rely on.

Our range includes:

  • metric and BS (imperial) sizes
  • no minimum order quantities
  • live stock availability
  • same-day dispatch before cut-off

Whether you need a single O-ring or larger quantities, we aim to make sourcing simple and reliable.


When to Choose NBR 70 (and When Not To)

Choose NBR 70 when:

  • sealing oils or fuels
  • working in moderate temperatures
  • general-purpose sealing

Shop here: Nitrile (NBR) O-Rings – Fuel, Oil & Hydraulic Seals | SealWithSelo – Seal with Selo

Consider alternatives when:

Choosing the right material ensures long-term performance.


In Summary

NBR 70 O-rings are popular for a reason — they offer a reliable, cost-effective and versatile sealing solution.

If your application involves:

  • oils or fuels
  • moderate temperatures
  • general engineering use

then NBR 70 is often the best starting point.

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