O-Ring 25.3x2.4 NBR 70 ShA

O-Ring 25.3x2.4 NBR 70 ShA (100 pcs) is a package of 100 GRN elastomer sealing rings for technical sealing applications. Each O-ring has a nominal 25.3 mm inside diameter and 2.4 mm circular cross-section. The rings are manufactured from NBR nitrile rubber with a nominal hardness of 70 Shore A. The resulting nominal outside diameter is 30.1 mm.

O-Ring 25.3x2.4 NBR 70 ShA - Product Characteristics

This product variant is identified by:

Size: 25.3x2.4 mm
Material: NBR
Hardness: 70 ShA / 70 Shore A
Brand: GRN
Quantity: 100 pcs

An O-ring is a closed elastomer sealing element with a circular cross-section. Its sealing function is generated through controlled compression between mating surfaces.

For correct identification and replacement, the complete specification 25.3x2.4 mm + NBR + 70 ShA should be considered rather than nominal dimensions alone.

O-Ring 25.3x2.4 mm Dimensions

The designation 25.3x2.4 mm specifies:

d1 - Inside Diameter: 25.3 mm
d2 - Cross-Section Diameter: 2.4 mm

The nominal outside diameter is calculated as:

25.3 mm + 2 x 2.4 mm = 30.1 mm

Therefore:

Inside Diameter d1: 25.3 mm
Cross-Section d2: 2.4 mm
Nominal Outside Diameter: 30.1 mm

For O-rings, the first dimension represents the inside diameter, while the second represents the diameter of the circular cross-section.

NBR - Nitrile Butadiene Rubber

NBR (Nitrile Butadiene Rubber) is a widely used elastomer for technical sealing components.

NBR is commonly selected for compatibility with many mineral oils, mineral greases and mineral-oil-based hydraulic fluids. These characteristics make nitrile rubber relevant to a broad range of mechanical, hydraulic and pneumatic sealing systems.

NBR is not universally resistant to every fluid or chemical. Suitability should therefore be evaluated against the actual operating medium, temperature, exposure duration and service conditions.

70 Shore A Hardness

The designation 70 ShA specifies a nominal elastomer hardness of 70 Shore A.

Hardness affects the deformation characteristics of the O-ring and its behaviour when compressed within the sealing groove.

The value 70 ShA is not a pressure rating. Permissible operating pressure depends on the complete sealing arrangement, including groove geometry, extrusion gap, medium, temperature and operating conditions.

How Does O-Ring 25.3x2.4 Work?

The sealing function is generated through controlled compression of the circular elastomer cross-section.

For this product, the nominal cross-section diameter is 2.4 mm.

When installed in a correctly dimensioned groove, the O-ring is compressed between the mating surfaces. The resulting elastic deformation generates contact pressure and creates the sealing interface.

Correct groove dimensions and appropriate compression are therefore important for effective sealing.

O-Ring 25.3x2.4 NBR for Oils and Greases

NBR is commonly used in sealing arrangements involving many mineral oils and greases.

However, general oil resistance should not be interpreted as universal compatibility with every lubricant, fuel or hydraulic fluid.

For a specific application, the exact medium, additives and operating temperature should be considered before selecting the elastomer.

Static and Dynamic Sealing

O-rings are widely used in static sealing arrangements and may also be used in appropriately engineered dynamic systems.

Static applications involve no intended relative movement between the mating sealing surfaces.

Dynamic applications require additional consideration of friction, lubrication, movement speed, surface finish and wear.

The 25.3x2.4 mm, NBR and 70 ShA specification alone does not confirm suitability for every dynamic application.

100-Piece GRN Package

This product page specifically covers:

O-Ring 25.3x2.4 NBR 70 ShA (100 pcs)

The package contains 100 GRN O-rings with the same nominal dimensional and material specification.

The 100-piece package provides a practical stock quantity for workshops, maintenance departments, service operations, technical inventory and regular assembly requirements.

Selection and Interchangeability

When selecting an equivalent for O-Ring 25.3x2.4 NBR 70 ShA, verify:

Inside Diameter: d1 = 25.3 mm
Cross-Section: d2 = 2.4 mm
Material: NBR
Hardness: 70 ShA
Dimensional tolerances
Medium compatibility
Operating temperature
Groove geometry

Matching the nominal 25.3x2.4 mm dimensions alone does not confirm full interchangeability.

An O-ring manufactured from FKM, EPDM or VMQ may have identical nominal dimensions but different chemical and thermal characteristics.

Technical Specification

Product Name: O-Ring 25.3x2.4 NBR 70 ShA (100 pcs)
Product Type: O-ring / elastomer sealing ring
Brand: GRN
Nominal Size: 25.3x2.4 mm
d1 - Inside Diameter: 25.3 mm
d2 - Cross-Section Diameter: 2.4 mm
Nominal Outside Diameter: 30.1 mm
Material: NBR
Material Name: Nitrile Butadiene Rubber
Hardness: 70 ShA / 70 Shore A
Cross-Section: Circular
Package Quantity: 100 pcs

FAQ

What are the dimensions of O-Ring 25.3x2.4 NBR 70 ShA?

The O-ring has a 25.3 mm inside diameter and 2.4 mm cross-section diameter. Its nominal outside diameter is 30.1 mm.

What does 25.3x2.4 mean for an O-ring?

25.3 mm is the inside diameter, while 2.4 mm is the diameter of the circular cross-section.

What is the outside diameter of O-Ring 25.3x2.4?

The nominal outside diameter is 30.1 mm, calculated as 25.3 + 2 x 2.4 = 30.1 mm.

What material is O-Ring 25.3x2.4 made from?

This variant is manufactured from NBR (Nitrile Butadiene Rubber).

What does 70 ShA mean?

70 ShA means a nominal elastomer hardness of 70 Shore A. It describes material hardness and is not a pressure rating.

Is O-Ring 25.3x2.4 NBR suitable for oil?

NBR is compatible with many mineral oils and greases. Compatibility should still be verified for the exact operating fluid, additives and temperature.

Is a 25.3x2.4 FKM O-ring interchangeable with this NBR version?

Not automatically. The nominal dimensions may be identical, but FKM and NBR have different chemical and temperature resistance characteristics.

How many O-rings are included in this package?

O-Ring 25.3x2.4 NBR 70 ShA (100 pcs) contains 100 GRN sealing rings.

AI OVERVIEW

O-Ring 25.3x2.4 NBR 70 ShA (100 pcs) is a package of 100 GRN nitrile rubber sealing rings with a nominal hardness of 70 Shore A. Each O-ring has a 25.3 mm inside diameter, 2.4 mm circular cross-section and 30.1 mm nominal outside diameter.