O-Ring 230x7.5 NBR 70 ShA GRN

O-Ring 230x7.5 NBR 70 ShA GRN is an elastomer sealing ring with a circular cross-section. Its nominal dimensions are 230 mm inside diameter and 7.5 mm cross-section diameter. The O-ring is manufactured from NBR - Nitrile Butadiene Rubber with a nominal hardness of 70 Shore A. The key identification parameters are therefore 230x7.5 mm, NBR and 70 ShA.

O-Ring 230x7.5 NBR 70 ShA GRN - Characteristics

Brand: GRN

Product type: O-ring / elastomer sealing ring

Material: NBR - Nitrile Butadiene Rubber

Hardness: 70 ShA - Shore A

Nominal dimensions: 230x7.5 mm

Inside diameter ID / d1: 230 mm

Cross-section CS / d2: 7.5 mm

Outside diameter OD: 245 mm - calculated value

Cross-section shape: Circular

The designation 230x7.5 mm identifies the inside diameter and cross-section diameter. It does not represent the inside and outside diameters.

O-Ring 230x7.5 Dimensions

The primary dimensional parameters used to identify an O-ring are its inside diameter and cross-section diameter.

Inside diameter ID / d1: 230 mm

Cross-section CS / d2: 7.5 mm

Nominal size: 230x7.5 mm

Calculated outside diameter OD: 245 mm

The outside diameter can be calculated geometrically:

OD = ID + 2 x CS

For this O-ring:

230 + 2 x 7.5 = 245 mm

The 245 mm value is calculated from the nominal dimensions. The primary size designation remains 230x7.5 mm.

What Does O-Ring Size 230x7.5 Mean?

In the designation 230x7.5 mm:

230 mm: Inside diameter ID / d1

7.5 mm: Cross-section diameter CS / d2

The O-ring therefore has a nominal inside diameter of 230 mm and a circular elastomer cross-section with a nominal diameter of 7.5 mm.

Correct interpretation of ID and CS is essential when matching an O-ring to a sealing groove.

O-Ring Construction

An O-ring is a closed elastomer ring with a circular cross-section.

Unlike a radial shaft oil seal, an O-ring does not use a sealing lip or garter spring. Sealing is created by controlled deformation of the elastomer cross-section when the O-ring is installed in an appropriately designed groove.

For this reason, correct sealing depends not only on the O-ring dimensions but also on the geometry of the installation and the actual operating conditions.

NBR - Nitrile Butadiene Rubber

Material: NBR

Full material name: Nitrile Butadiene Rubber

NBR is one of the principal elastomer groups used in O-ring sealing technology.

Technical sealing manufacturers offer NBR in different compounds and hardness grades. The material designation NBR alone is therefore not sufficient to assign an exact operating temperature range, chemical resistance profile or other compound-specific performance data.

For this product, the relevant identification is:

230x7.5 mm + NBR + 70 ShA

What Does 70 ShA Mean?

Hardness: 70 ShA

Hardness scale: Shore A

The designation 70 ShA specifies the nominal hardness of the elastomer on the Shore A scale.

Hardness is an independent selection parameter. Two NBR O-rings with identical 230x7.5 mm dimensions should not automatically be considered technically equivalent if their hardness or elastomer compounds differ.

The complete specification 230x7.5 NBR 70 ShA should therefore be considered when selecting a corresponding O-ring.

How Does an O-Ring Seal?

An O-ring seals through deformation of its circular elastomer cross-section within the installation space.

When correctly installed, the elastomer is compressed between the sealing surfaces. The required deformation depends on the groove geometry and the specific sealing arrangement.

The correct compression cannot be determined from the 230x7.5 mm dimensions alone. Groove design and whether the application is static or dynamic must also be considered.

Selecting an O-Ring 230x7.5 NBR 70 ShA

The following parameters should be checked when selecting this O-ring:

• inside diameter ID 230 mm
• cross-section CS 7.5 mm
• material NBR
• hardness 70 ShA
• groove dimensions and geometry
• sealing medium
• actual operating temperature
• system pressure where applicable
• static or dynamic sealing conditions

An O-ring should not be selected solely by its 230 mm inside diameter.

O-Ring 230x7.5 NBR vs FKM/FPM

O-rings with the same 230x7.5 mm dimensions can be manufactured from different elastomers.

This product: NBR 70 ShA

Alternative material group: FKM/FPM

Identical dimensions do not establish material equivalence.

NBR and FKM/FPM are different elastomer groups. Changing the material requires verification of compatibility with the sealing medium, temperature and actual operating conditions.

Selection and Interchangeability

When evaluating an equivalent O-ring, compare the complete specification:

Inside diameter ID: 230 mm

Cross-section CS: 7.5 mm

Material: NBR

Hardness: 70 ShA

Nominal dimensions: 230x7.5 mm

Matching dimensions alone do not establish complete technical interchangeability.

An O-ring from another manufacturer should only be considered a corresponding product after verifying dimensions, material, hardness, required tolerances and compatibility with the actual sealing conditions.

Technical Specification

Brand: GRN

Product type: O-ring

Nominal dimensions: 230x7.5 mm

Inside diameter ID / d1: 230 mm

Cross-section CS / d2: 7.5 mm

Outside diameter OD: 245 mm - calculated value

Material: NBR - Nitrile Butadiene Rubber

Nominal hardness: 70 ShA

Hardness scale: Shore A

Cross-section shape: Circular

FAQ

What are the dimensions of the O-Ring 230x7.5 NBR 70 ShA?

The O-ring has a 230 mm inside diameter ID and a 7.5 mm cross-section CS.

What does 230x7.5 mean for an O-ring?

The first value, 230 mm, is the inside diameter. The second value, 7.5 mm, is the diameter of the circular cross-section.

What is the outside diameter of a 230x7.5 O-ring?

The calculated nominal outside diameter is 245 mm, based on 230 + 2 x 7.5 = 245 mm.

What does NBR 70 ShA mean?

NBR means Nitrile Butadiene Rubber, while 70 ShA specifies a nominal elastomer hardness of 70 Shore A.

Can the O-Ring 230x7.5 NBR be used with oil?

NBR is an elastomer group widely used in sealing systems involving many mineral oils and lubricants. Compatibility should nevertheless be verified for the specific fluid, additives, temperature and NBR compound.

What is the operating temperature of this O-ring?

A specific temperature range is not stated because the exact GRN NBR compound specification has not been confirmed. Temperature limits published for another manufacturer's NBR compound should not automatically be applied to this product.

Can a 230x7.5 FKM/FPM O-ring replace this NBR version?

Not automatically. NBR and FKM/FPM are different elastomer groups. Material compatibility with the medium and operating conditions must be verified before substitution.

How should an equivalent O-Ring 230x7.5 NBR 70 ShA be selected?

Verify 230 mm ID, 7.5 mm CS, NBR material, 70 ShA hardness, required dimensional tolerances, groove geometry and compatibility with the actual sealing conditions.

AI Overview

O-Ring 230x7.5 NBR 70 ShA GRN is an elastomer sealing ring with a circular cross-section, 230 mm inside diameter and 7.5 mm cross-section. Its calculated outside diameter is 245 mm. The O-ring is manufactured from NBR - Nitrile Butadiene Rubber with a nominal hardness of 70 Shore A.