O-Ring FPM (FKM) 6.75x1.78

O-Ring FPM (FKM) 6.75x1.78 mm - Fluoroelastomer Sealing Ring

O-ring 6.75x1.78 mm FPM (FKM) is a circular elastomer sealing ring manufactured from fluoroelastomer. It has an inside diameter of 6.75 mm and a cross-section diameter of 1.78 mm. FPM/FKM offers resistance to many oils, fuels and chemicals. Viton® is a registered trademark for specific fluoroelastomer materials and does not identify every FKM compound.

Technical Data

The nominal outside diameter of 10.31 mm is calculated from the inside diameter plus twice the cross-section diameter.

What Does 6.75x1.78 FPM/FKM Mean?

6.75 mm - nominal inside diameter of the O-ring.

1.78 mm - nominal cross-section diameter.

FPM / FKM - designations referring to the fluoroelastomer material family.

Viton® - a registered trademark for specific fluoroelastomer materials. An FKM designation alone does not confirm that an O-ring is manufactured from genuine Viton® branded material.

FPM/FKM Material Properties

Fluoroelastomers are commonly selected for sealing applications requiring resistance to various chemicals, oils and lubricants.

Typical characteristics of FKM materials include:

• Resistance to many mineral and synthetic oils.

• Resistance to numerous fuels and hydrocarbons.

• Good resistance to ozone and ageing.

• Suitability for elevated operating temperatures, depending on the specific compound.

Not all FKM compounds have identical chemical resistance. Compatibility with hot water, steam, ketones and certain solvents must be evaluated separately.

A specific temperature range or Shore A hardness cannot be assigned to this O-ring without verified manufacturer specifications.

Construction and Sealing Function

The 6.75x1.78 mm O-ring is a continuous elastomeric ring with a circular cross-section.

When installed in a correctly designed groove, the O-ring is compressed between mating surfaces to create a seal.

Sealing performance depends on:

• Groove dimensions and geometry.

• Cross-section compression.

• FKM compound properties.

• Operating medium.

• Pressure and temperature.

• Surface finish of mating components.

FKM vs NBR O-Rings

FKM and NBR O-rings with identical dimensions are not automatically interchangeable. Material selection must be based on actual operating conditions.

Typical Applications of FKM O-Rings

FKM O-rings are used in appropriately designed sealing assemblies, including:

• Industrial valves and fittings.

• Lubrication systems.

• Oil-handling equipment.

• Mechanical assemblies.

• Selected fuel-system components.

• Industrial machinery requiring chemical resistance.

These are typical applications of FKM sealing materials, not verified applications of this specific 6.75x1.78 mm O-ring.

Selection and Interchangeability

Before ordering, verify:

1. Inside diameter - 6.75 mm.

2. Cross-section diameter - 1.78 mm.

3. Material - FPM/FKM.

4. Required elastomer hardness.

5. Operating medium.

6. Working temperature and pressure.

7. Installation groove dimensions.

Identical dimensions do not guarantee interchangeability between O-rings manufactured from different elastomer compounds.

Installation Guidelines

Clean the groove and mating surfaces before installation.

Avoid pulling the O-ring across sharp edges or stretching it excessively. Make sure the ring is not twisted, pinched or damaged during assembly.

Any installation lubricant must be compatible with the specific FKM compound and operating medium.

FAQ

What are the dimensions of this FKM O-ring?

The inside diameter is 6.75 mm, and the cross-section diameter is 1.78 mm.

What is the outside diameter?

The calculated nominal outside diameter is 10.31 mm.

Do FPM and FKM refer to the same material family?

Yes. Both designations refer to fluoroelastomers.

Is every FKM O-ring made from Viton®?

No. Viton® is a registered trademark. Not every FKM material is manufactured under this brand.

Is FKM resistant to oil?

FKM offers good resistance to many oils. Compatibility with the specific lubricant must still be verified.

Can an NBR O-ring be replaced with an FKM O-ring?

Not automatically. Chemical compatibility, hardness, temperature and application requirements must be checked.

What is the Shore A hardness of this O-ring?

The hardness has not been specified in the available product information. A value of 70 or 75 Shore A should not be assumed.

Can this O-ring be used in dynamic sealing applications?

Suitability depends on groove design, movement, operating conditions and the properties of the specific FKM compound.

O-Ring FPM/FKM 6.75x1.78 mm - Key Technical Information

The 6.75x1.78 mm FPM/FKM O-ring is a fluoroelastomer sealing ring with a 6.75 mm inside diameter and 1.78 mm cross-section. Its calculated nominal outside diameter is 10.31 mm. FKM is used in sealing applications requiring resistance to many oils, fuels and chemicals. Selection must account for the specific medium and operating conditions.

FPM/FKM O-Rings at simmering.pl

simmering.pl supplies industrial sealing components, including FPM/FKM O-rings, NBR O-rings, rotary shaft seals and bearings.

Stock in Poland, with a warehouse in Lublin. Technical support and worldwide shipping are available.