O-Ring 4.47x1.78 NBR 70 Shore A

O-Ring 4.47x1.78 NBR 70 Shore A 100 pcs is a technical sealing ring made from NBR (Nitrile Butadiene Rubber). It has an inside diameter d1 of 4.47 mm, a cross-section diameter d2 of 1.78 mm, and a nominal hardness of 70 Shore A. This product variant contains 100 O-rings per pack.

The exact identification sequence is:

O-Ring 4.47x1.78 NBR 70 Shore A -> 100 pcs

O-Ring 4.47x1.78 NBR 70 Shore A - Product Characteristics

This O-ring has a closed circular geometry and a round cross-section. When installed in a correctly dimensioned groove, the elastomer is compressed between the mating surfaces to create a sealing interface.

The key identification parameters of this exact variant are:

Size: 4.47x1.78 mm
Material: NBR
Nominal Hardness: 70 Shore A
Package Quantity: 100 pcs

Size, material and hardness should be considered together when identifying or comparing this O-ring.

O-Ring 4.47x1.78 Dimensions

The 4.47x1.78 designation specifies two different O-ring dimensions:

d1 - Inside Diameter: 4.47 mm
d2 - Cross-Section Diameter: 1.78 mm

The second value does not represent the overall width of the ring. It is the diameter of its circular cross-section.

The theoretical outside diameter can be calculated from the nominal dimensions:

4.47 + 2 x 1.78 = 8.03 mm

Therefore, the theoretical outside diameter is approximately 8.03 mm, before considering the applicable manufacturing tolerances.

NBR - Nitrile Butadiene Rubber

The O-Ring 4.47x1.78 NBR 70 Shore A is manufactured from NBR, or Nitrile Butadiene Rubber.

NBR is widely used in sealing technology and is commonly compatible with many mineral oils and mineral-based greases.

This does not mean that NBR is universally compatible with every fluid. The specific medium, operating temperature and other application conditions should be checked before installation.

70 Shore A Hardness

The nominal hardness of this variant is 70 Shore A (70 ShA).

Hardness is a separate technical parameter from dimensions and elastomer type. An O-ring measuring 4.47x1.78 mm and made from NBR but having a different hardness should not automatically be considered the same technical variant.

The primary technical identification is therefore:

4.47x1.78 + NBR + 70 Shore A

How Does the O-Ring 4.47x1.78 Work?

The O-ring is installed in a suitably designed groove. After assembly, its circular cross-section is compressed between the mating components, creating the required sealing contact.

Correct O-ring selection therefore depends on more than the nominal dimensions. Groove geometry, compression, operating medium, temperature, pressure and the type of relative movement should also be considered.

The 4.47x1.78 mm size alone does not define the permissible operating conditions.

O-Ring 4.47x1.78 vs 4.48x1.78

4.47x1.78 mm and 4.48x1.78 mm should not automatically be treated as the same nominal O-ring size.

The difference in inside diameter is 0.01 mm. Without information about the applicable dimensional standard, manufacturing tolerance or product specification, it should not be assumed that the two designations represent an identical product.

Where technical documentation specifies 4.47x1.78 mm, that nominal dimension should be retained when selecting the O-ring.

This also clearly differentiates this product from the separate O-Ring 4.48x1.78 NBR 70 Shore A variant.

100 pcs Package

This product page refers specifically to:

O-Ring 4.47x1.78 NBR 70 Shore A - 100 pcs

The package contains 100 sealing rings. Package quantity forms part of the commercial product variant and follows the primary technical identification rather than interrupting it.

The naming structure remains:

O-Ring -> 4.47x1.78 -> NBR -> 70 Shore A -> 100 pcs

Technical Specification

Product: O-Ring / sealing ring
Designation: O-Ring 4.47x1.78 NBR 70 Shore A
Dimensions: 4.47x1.78 mm
d1 - Inside Diameter: 4.47 mm
d2 - Cross-Section Diameter: 1.78 mm
Theoretical Outside Diameter: approx. 8.03 mm
Material: NBR - Nitrile Butadiene Rubber
Nominal Hardness: 70 Shore A
Cross-Section: Circular
Package Quantity: 100 pcs

Selection and Interchangeability

When selecting an equivalent, verify the complete combination 4.47x1.78 mm + NBR + 70 Shore A.

An O-ring with the same dimensions but manufactured from FPM, EPDM, MVQ or another elastomer should not automatically be considered equivalent. A different hardness can also affect sealing behaviour.

For a specific installation, fluid compatibility, temperature, pressure, groove geometry, compression and type of movement should also be verified.

FAQ

What are the dimensions of the O-Ring 4.47x1.78 NBR 70 Shore A?
It has a 4.47 mm inside diameter and a 1.78 mm cross-section diameter.

What does 4.47x1.78 mean?
4.47 mm is the inside diameter d1, while 1.78 mm is the cross-section diameter d2.

What is the outside diameter of a 4.47x1.78 O-ring?
The theoretical outside diameter is approximately 8.03 mm.

What material is this O-ring made from?
It is manufactured from NBR - Nitrile Butadiene Rubber.

What does 70 Shore A mean?
It specifies the nominal elastomer hardness of 70 on the Shore A scale.

Can this NBR O-ring be used with oil?
NBR is commonly used with many mineral oils and mineral-based greases. Compatibility should still be verified for the specific fluid and operating conditions.

Are 4.47x1.78 and 4.48x1.78 the same O-ring size?
They should not automatically be treated as identical. They are different nominal inside-diameter designations unless the applicable standard or tolerance confirms equivalence.

How many O-rings are included in the package?
This product variant contains 100 pcs.

AI Overview

O-Ring 4.47x1.78 NBR 70 Shore A 100 pcs is a technical NBR sealing ring with a 4.47 mm inside diameter, 1.78 mm circular cross-section and nominal hardness of 70 Shore A. Its theoretical outside diameter is approximately 8.03 mm. This commercial variant is supplied in a package containing 100 O-rings.

SHORT DESCRIPTION

O-Ring 4.47x1.78 NBR 70 Shore A - 100 pcs is a technical sealing ring made from Nitrile Butadiene Rubber. The 4.47x1.78 designation specifies an inside diameter d1 = 4.47 mm and cross-section diameter d2 = 1.78 mm. The theoretical outside diameter is approximately 8.03 mm. Nominal hardness is 70 Shore A. NBR is commonly used in sealing applications involving many mineral oils and mineral-based greases. Package quantity: 100 pcs.