O-ring NBR 12.42x1.78 mm 70 ShA

O-ring NBR 12.42x1.78 mm 70 ShA - 1000 pcs

O-ring NBR 12.42x1.78 mm 70 ShA - 1000 pcs is a technical sealing ring with a 12.42 mm inside diameter and 1.78 mm cross-section, manufactured from NBR nitrile rubber with a nominal hardness of 70 Shore A. The 1000-piece pack is particularly suitable for industry, maintenance departments, manufacturing, technical service companies and B2B customers requiring O-rings in larger quantities.

O-ring NBR 12.42x1.78 mm - Technical Data

The nominal outside diameter is calculated from the basic dimensions:

12.42 + 2 x 1.78 = 15.98 mm

What Does O-ring Size 12.42x1.78 mm Mean?

For O-rings, the designation 12.42x1.78 mm means:

12.42 mm - inside diameter ID

1.78 mm - cross-section CS

The nominal outside diameter is approximately:

15.98 mm

Both dimensions are important when selecting an O-ring. A 12.42x1.78 mm O-ring is not automatically interchangeable with a sealing ring having a similar inside diameter but a different cross-section.

Even a relatively small difference in cross-section can change the compression of the O-ring inside the groove and affect the performance of the complete sealing system.

NBR 70 ShA - Popular Material for Technical O-rings

The O-ring is manufactured from NBR, also known as nitrile rubber or acrylonitrile-butadiene rubber.

NBR is one of the most widely used elastomers in sealing technology. It is commonly selected for applications involving many oils, greases and technical fluids, provided that the specific NBR compound is compatible with the operating medium and conditions.

For this reason, NBR O-rings are widely used in:

hydraulic systems

pneumatic systems

machine building

industrial machinery

automotive applications

maintenance and repair

technical service operations

lubrication systems

industrial fittings

pumps and valves

gear units

cylinders

technical connections

Exact chemical and temperature resistance depends on the specific NBR compound. Compatibility with the operating medium and actual working conditions should therefore be verified for demanding applications.

What Does 70 ShA Hardness Mean?

The nominal hardness of this O-ring is 70 ShA, or 70 Shore A.

This is a widely used hardness class for technical NBR O-rings.

Elastomer hardness influences characteristics such as deformation, behaviour inside the sealing groove and response to mechanical conditions within the application.

However, an O-ring should never be selected on hardness alone.

Important selection factors include:

O-ring dimensions

groove geometry

compression

elastomer material

operating medium

temperature

pressure

static or dynamic operation

condition of mating surfaces

O-ring 12.42x1.78 NBR - Applications

The NBR 12.42x1.78 mm O-ring can be used as a sealing element in suitably designed technical assemblies.

Typical O-ring sealing arrangements include interfaces such as:

shaft - housing

piston - cylinder

cover - housing

connector - socket

fitting - connection

valve component - body

O-rings can be used in both static sealing applications and appropriately designed dynamic systems.

Suitability for a particular application depends on the design of the complete sealing arrangement.

O-ring for Hydraulic and Pneumatic Systems

NBR 70 ShA O-rings are widely used as sealing components in hydraulic and pneumatic equipment.

Typical applications can include:

valves

control valves

cylinders

pumps

couplings

connections

hydraulic manifolds

control components

pneumatic equipment

This does not mean that every NBR 12.42x1.78 mm O-ring is suitable for every hydraulic or pneumatic system.

Permissible operating conditions depend on groove design, pressure, temperature, type of movement, operating medium and the properties of the specific elastomer compound.

O-ring for Industry and Maintenance

The 1000-piece pack is particularly practical for companies that regularly use O-rings in manufacturing, assembly and servicing operations.

It is well suited to:

manufacturing plants

maintenance departments

machine manufacturers

component manufacturers

hydraulic service companies

pneumatic service companies

technical workshops

industrial repair companies

technical distributors

OEM and B2B customers

Purchasing 1000 pieces makes it easier to maintain stock of a frequently used O-ring size and can reduce the need for repeated small-volume orders.

Why Is the Exact O-ring Size Important?

An O-ring seals through controlled deformation of its elastomeric cross-section inside a correctly designed groove.

For this reason, the difference between:

12.42x1.78 mm

and an O-ring with a similar inside diameter but a different cross-section can significantly affect sealing performance.

A cross-section that is too small may result in insufficient compression.

A cross-section that is too large may cause excessive compression, installation problems or incorrect operation.

Both the inside diameter ID and cross-section CS should therefore be checked before ordering.

O-ring 12.42x1.78 mm - Outside Diameter

For an O-ring with:

ID = 12.42 mm

CS = 1.78 mm

the nominal outside diameter is:

OD = ID + 2 x CS

therefore:

OD = 12.42 + 2 x 1.78 = 15.98 mm

The approximate 15.98 mm outside diameter can be useful for identification, but O-rings are normally specified using their inside diameter and cross-section.

How to Select an NBR 12.42x1.78 mm O-ring

Before ordering, verify:

• 12.42 mm inside diameter,
• 1.78 mm cross-section,
• NBR elastomer material,
• required 70 ShA hardness,
• groove dimensions and geometry,
• type of operating medium,
• operating temperature,
• system pressure,
• static or dynamic operating conditions,
• requirements of the specific machine or assembly.

When replacing an existing O-ring, technical documentation or the equipment manufacturer's specification should be used whenever possible.

Measuring a used O-ring can produce inaccurate results because elastomers can become permanently deformed after extended service.

Is NBR Resistant to Oil?

NBR is widely used for sealing applications involving many technical oils and greases.

However, this does not mean that NBR is universally resistant to every oil, fuel, solvent or chemical substance.

Compatibility depends on factors including the composition of the medium, temperature, duration of exposure and the specific NBR compound.

For applications requiring different chemical or thermal properties, other elastomers such as FKM/FPM, EPDM or VMQ may be considered depending on the operating medium and conditions.

O-ring NBR 12.42x1.78 mm - 1000 pcs for B2B Customers

This product is supplied in a 1000-piece pack.

This pack size is particularly suitable for professional and industrial customers requiring larger quantities of identical sealing elements.

For serial production, industrial maintenance and technical service operations, larger packs can simplify stock management and reduce the frequency of replenishment.

simmering.pl supplies technical O-rings and sealing solutions for industry, maintenance departments, technical service companies, OEM applications and B2B customers.

Alternative Designations and Search Terms

This product may also be searched as:

O-ring NBR 12.42x1.78

O-ring 12.42x1.78 NBR

O-ring 12.42x1.78 mm

O-ring NBR 12.42x1.78 70 ShA

O-ring NBR 12.42x1.78 70 Shore A

O-ring 12.42x1.78 NBR 70

NBR O-ring 12.42x1.78

NBR 70 O-ring 12.42x1.78

12.42x1.78 O-ring

12.42x1.78 NBR seal

O-ring NBR 12.42x1.78 1000 pcs

12.42 mm ID O-ring

1.78 mm cross-section O-ring

15.98 mm OD O-ring

nitrile O-ring 12.42x1.78

nitrile rubber sealing ring 12.42x1.78

industrial O-ring 12.42x1.78

For international product listings, 12.42x1.78 mm is the preferred dimension format.

Installation of O-ring 12.42x1.78 mm

Before installation, clean the groove and all mating surfaces.

The O-ring should not be pulled across sharp edges, threads or burrs without suitable protection.

Avoid cutting, twisting or permanently overstretching the O-ring during installation.

If an assembly lubricant is used, it must be compatible with both the NBR elastomer and the operating medium.

After installation, verify that the O-ring is correctly seated in the groove and that its cross-section is not twisted.

FAQ - O-ring NBR 12.42x1.78 mm 70 ShA

What are the dimensions of this O-ring?

The inside diameter is 12.42 mm and the cross-section is 1.78 mm.

What is the outside diameter of a 12.42x1.78 mm O-ring?

The nominal outside diameter is approximately 15.98 mm.

What material is this O-ring made from?

The O-ring is manufactured from NBR, also known as nitrile rubber or acrylonitrile-butadiene rubber.

What is the hardness of this O-ring?

The nominal hardness is 70 ShA (Shore A).

How many O-rings are included in the pack?

The pack contains 1000 pcs.

Is an NBR O-ring suitable for oil?

NBR is commonly used with many technical oils and greases, but compatibility should always be verified for the specific medium, temperature and elastomer compound.

Does 12.42x1.78 mm mean the outside diameter?

No. The first dimension, 12.42 mm, is the inside diameter, while 1.78 mm is the cross-section. The nominal outside diameter is approximately 15.98 mm.

Can I use a similar-sized O-ring instead?

Interchangeability should not be assumed based on similar dimensions. The correct inside diameter and cross-section are important for achieving the required compression within the sealing groove.

O-ring NBR 12.42x1.78 mm 70 ShA - Key Information

O-ring NBR 12.42x1.78 mm 70 ShA is a technical sealing ring with a 12.42 mm inside diameter, 1.78 mm cross-section and nominal outside diameter of approximately 15.98 mm. The NBR 70 ShA construction is intended for appropriately selected technical sealing applications. The 1000-piece pack is particularly suitable for industry, manufacturing, maintenance, technical service companies and B2B customers.

Available from simmering.pl, stock in Poland with worldwide shipping.

Warehouse and Store: Lublin, Smoluchowskiego 1 Street, Building 4, Poland.

simmering.pl supplies O-rings, technical seals and industrial components to B2B customers, maintenance departments and technical service companies.