O-ring NBR 25x2 mm

Applications & Typical Use

The O-ring 25x2 NBR 70 ShA in bulk pack of 1000 pcs is tailored for demanding industrial applications where cost-efficiency, consistency, and performance matter. Widely used in hydraulic and pneumatic systems, gearboxes, pumps, valves, and machine assemblies, this seal also integrates well with bearing housings or bearing units, protecting ball bearings from leakage or contamination. Thanks to its balanced properties, it’s suitable wherever a reliable, oil-resistant tubing or sealing interface is needed across large-scale production or maintenance tasks.

Because nitrile rubber (NBR) offers good resistance to mineral oils, greases, and many common fluids, this variant becomes a cost-effective standard for B2B buyers seeking a high-volume sealing solution without compromising essential performance.

Key Advantages & Material Features

• High volume cost efficiency - ordering in 1000-piece lots significantly lowers per-unit cost and streamlines inventory for large operations.

• Oil and grease resistance - NBR 70 ShA delivers dependable performance with many petroleum-based lubricants and oils, making it well-suited for machine maintenance environments.

• Balanced hardness - the 70 ShA rating provides a good compromise between elasticity and structural integrity, delivering sealing pressure without brittleness.

• Dimensional stability & repeatability - manufactured within tight tolerances, ensuring uniform sealing behavior across all 1000 units.

• Compact cross-section - with just 2 mm thickness, it fits in constrained grooves while still offering reliable contact.

• Versatility in sealing regimes - effective for static sealing and light dynamic movement (e.g. low-frequency reciprocation), making it useful in cross-sectional sealing tasks in machines.

Technical Specifications

Installation Guidance & Best Practices

• Design the sealing groove (gland) to permit a moderate squeeze—excessive compression will shorten lifetime, while insufficient contact may lead to leakage.

• Use lubricants compatible with NBR (e.g. light silicone grease or NBR-approved oils) to ease assembly, reduce friction, and protect seal edges.

• Avoid exposure to strong oxidizing agents, acids, prolonged UV, and ozone which can degrade NBR over time.

• When mounted near ball bearings or inside bearing housings, ensure the O-ring is not subject to shearing edges or sharp transitions that could cut the seal.

• Store in a cool, dry, shaded environment, away from ozone sources and direct sunlight to preserve the elastomer’s flexibility.

FAQ - Frequently Asked Questions

Q1. Why choose a pack of 1000 pieces?
Bulk packaging enables lower cost per unit, ensures sufficient reserves for maintenance cycles, and reduces the frequency of reorder in industrial settings.

Q2. Can O-ring 25x2 NBR 70 ShA handle contact with engine or hydraulic oils?
Yes — NBR is widely known for its compatibility with many mineral oils and greases, making this seal suitable in many oil-based systems.

Q3. How long can these seals last in service?
Under moderate operating conditions (below 100 °C, clean media, low movement), they can last multiple years. In harsher environments, regular inspections are advisable.

Q4. Is this suitable for dynamic sealing (rotating shafts or sliding parts)?
It can be used for light dynamic motion (slow reciprocating, minor axial displacement), but for high-speed rotation or heavy sliding, elastomers like FKM may outperform NBR.

Q5. What does “70 ShA” mean and how it affects performance?
“70 ShA” denotes the hardness of the rubber on the Shore A scale — 70 is a mid-to-firm hardness that offers a good balance of sealing force and flexibility.