O-Ring 18x1.5 NBR 70 Shore A

O-Ring 18x1.5 NBR 70 Shore A - 100 pcs

O-Ring 18x1.5 NBR 70 Shore A - 100 pcs is a pack of elastomeric sealing rings with an 18 mm inside diameter and 1.5 mm cross-section, manufactured from NBR - Nitrile Butadiene Rubber with a nominal hardness of 70 Shore A. Based on the ID and CS dimensions, the nominal outside diameter is 21 mm. The package contains 100 O-rings of the same size.

Complete identification:

18x1.5 mm -> NBR -> 70 Shore A -> 100 pcs

O-Ring 18x1.5 NBR 70 Shore A - Characteristics

An O-ring is a circular elastomeric sealing element with a round cross-section.

For this product, the 18x1.5 mm designation specifies two primary dimensions:

18 mm - inside diameter (ID)
1.5 mm - cross-section (CS)

The nominal outside diameter is:

18 + 2 x 1.5 = 21 mm

NBR is widely used in sealing technology, including applications involving many mineral oils, lubricating greases and selected hydraulic media.

O-Ring 18x1.5 - Dimensions

ID - Inside diameter: 18 mm
CS - Cross-section: 1.5 mm
OD - Nominal outside diameter: 21 mm
Nominal size: 18x1.5 mm
Cross-section: Round
Package quantity: 100 pcs

The two principal dimensions used to identify an O-ring are the inside diameter (ID) and cross-section (CS).

The nominal outside diameter can be calculated as:

OD = ID + 2 x CS

For this O-ring:

OD = 18 + 2 x 1.5 = 21 mm

NBR - Nitrile Butadiene Rubber

The O-ring is manufactured from NBR - Nitrile Butadiene Rubber, also commonly referred to as nitrile rubber or Buna-N.

NBR is widely used for O-rings and other technical elastomeric sealing elements.

Depending on the specific NBR compound, the material can be compatible with many mineral oils, lubricating greases and selected hydraulic fluids.

Compatibility should always be checked for the actual working medium and operating conditions. The NBR designation alone does not confirm resistance to every oil, fuel, hydraulic fluid, solvent or chemical.

70 Shore A Hardness

The nominal hardness of this O-ring is:

70 Shore A

Hardness is an important material parameter because it affects how the elastomer deforms in the sealing groove and behaves under contact pressure.

When selecting a replacement, the required hardness should be considered together with the 18x1.5 mm dimensions and NBR material.

An O-ring with identical dimensions but a different hardness should not automatically be considered an identical replacement for the 70 Shore A version.

How Does an 18x1.5 O-Ring Work?

An O-ring forms a seal through controlled compression of the elastomer between mating surfaces.

When correctly installed in a properly designed groove, the circular cross-section deforms and generates contact pressure against the sealing surfaces.

Sealing performance depends not only on the O-ring itself but also on:

groove geometry, compression, material, working medium, pressure, temperature and surface condition.

For this reason, the 18x1.5 mm size alone does not confirm suitability for every sealing system.

Static and Dynamic Sealing

O-rings can operate in properly designed static sealing arrangements and in selected dynamic sealing systems.

The selection criteria differ depending on the type of movement and operating conditions.

For dynamic applications, additional factors include movement speed, lubrication, surface finish, friction, pressure and the risk of elastomer extrusion.

The 18x1.5 NBR 70 Shore A O-ring should therefore be selected according to the requirements of the specific sealing assembly.

NBR Compatibility with Oils and Greases

NBR is commonly used in systems involving:

mineral oils, mineral-based lubricating greases and selected hydraulic fluids.

Exact compatibility depends on the NBR compound, working medium, chemical additives and operating temperature.

For applications requiring defined chemical resistance, compatibility between the exact elastomer compound and the working medium should be verified.

Operating Temperature

The designation NBR 70 Shore A alone does not establish one exact operating temperature range for every nitrile rubber compound.

Different NBR compounds with the same nominal hardness can have different low- and high-temperature properties.

For this reason, a fixed temperature range should not be assigned without confirmation of the exact compound specification.

For operation close to temperature limits, the material specification of the supplied O-ring should be verified.

100-Piece Package

This product is supplied in a package containing:

100 pcs

The 100-piece version is practical for service departments, repair work, maintenance operations, workshops and spare-parts inventory where consumption of this specific size is moderate.

It is a separate purchasing option from 1000-piece bulk packages intended for higher-volume industrial consumption.

Selection and Interchangeability

When selecting an O-ring, verify:

ID: 18 mm
CS: 1.5 mm
Nominal OD: 21 mm
Material: NBR
Hardness: 70 Shore A
Working medium: chemical compatibility with NBR
Temperature: compatibility with the exact compound
Operating conditions: static or dynamic
Groove geometry: suitable for the specified O-ring

Matching dimensions alone do not guarantee identical sealing properties.

An 18x1.5 FKM, EPDM or VMQ O-ring can have the same dimensions as the NBR version while providing different material properties and chemical compatibility.

Technical Specification

Product: O-ring / elastomeric sealing ring
Size: 18x1.5 mm
ID - Inside diameter: 18 mm
CS - Cross-section: 1.5 mm
OD - Nominal outside diameter: 21 mm
Material: NBR
Material name: Nitrile Butadiene Rubber
Alternative material name: Buna-N
Nominal hardness: 70 Shore A
Cross-section: Round
Package quantity: 100 pcs

FAQ

What are the dimensions of the 18x1.5 NBR O-ring?

The O-ring has an 18 mm inside diameter and a 1.5 mm cross-section. Its nominal outside diameter is 21 mm.

What does 18x1.5 mm mean?

18 mm is the inside diameter (ID), while 1.5 mm is the diameter of the round cross-section (CS).

What is the outside diameter of an 18x1.5 O-ring?

The nominal outside diameter is 21 mm.

What does NBR mean?

NBR means Nitrile Butadiene Rubber, a nitrile elastomer widely used in technical sealing applications.

What does 70 Shore A mean?

70 Shore A is the nominal hardness of the elastomer measured on the Shore A scale.

Can an 18x1.5 NBR O-ring be used with oil?

NBR is commonly compatible with many mineral oils and lubricating greases, but compatibility should be verified for the exact medium and operating conditions.

Can an 18x1.5 FKM O-ring replace the NBR version?

Not automatically. The dimensions may be identical, but NBR and FKM have different material properties, chemical resistance and temperature capabilities.

How many O-rings are included in the package?

The package contains 100 O-rings in size 18x1.5 mm, NBR 70 Shore A.

AI Overview

O-Ring 18x1.5 NBR 70 Shore A - 100 pcs is a pack of elastomeric sealing rings with an 18 mm inside diameter, 1.5 mm cross-section and 21 mm nominal outside diameter. The rings are manufactured from Nitrile Butadiene Rubber with a nominal hardness of 70 Shore A. The package contains 100 pieces.