FKM FPM Viton O-Ring 15x3.5 - Fluoroelastomer Seal

FKM/FPM Viton O-Ring 15x3.5 mm - Fluoroelastomer Sealing Ring

FKM/FPM Viton O-Ring 15x3.5 mm is an elastomeric sealing ring with a nominal inside diameter of 15 mm and a cross-sectional diameter of 3.5 mm, manufactured from FKM/FPM fluoroelastomer. O-rings made from this material are commonly used in sealing applications requiring resistance to many oils, lubricating greases, fuels and elevated temperatures. They are primarily suitable for correctly designed static sealing arrangements and may also be used in selected dynamic applications.

Viton is a registered trademark for specific fluoroelastomer materials. The FKM/FPM designation alone does not confirm that the O-ring is manufactured from genuine Viton-branded material.

Technical Specifications - FKM/FPM O-Ring 15x3.5 mm

FKM/FPM O-Ring 15x3.5 mm - Dimensions Explained

The designation 15x3.5 mm identifies two essential dimensions:

• 15 mm - nominal inside diameter of the O-ring.

• 3.5 mm - nominal cross-sectional diameter.

The nominal outside diameter is calculated as follows:

15 mm + 2 x 3.5 mm = 22 mm.

Therefore, the nominal dimensions are:

• Inside diameter: 15 mm.

• Cross-section: 3.5 mm.

• Outside diameter: 22 mm.

When selecting an O-ring, the groove dimensions, required compression, dimensional tolerances and operating conditions must also be considered.

Why Is the Cross-Section Important?

The cross-sectional diameter determines how the O-ring interacts with the sealing groove and mating surfaces.

Incorrect cross-sectional dimensions can result in insufficient compression, excessive deformation or premature sealing failure.

Is the Outside Diameter Always Exactly 22 mm?

No. The calculated outside diameter is nominal.

Actual measurements may vary according to manufacturing tolerances and the condition of the elastomer.

What Do FKM, FPM and Viton Mean?

FKM - Fluoroelastomer

FKM is a designation for a family of fluorocarbon elastomers used in industrial sealing components.

These materials are valued for their resistance to many petroleum-based substances and their suitability for elevated-temperature applications.

FPM - Alternative Material Designation

FPM is another designation for the same general family of fluoroelastomer materials.

Common product names include:

• FKM O-ring.

• FPM O-ring.

• Fluoroelastomer O-ring.

• FKM rubber sealing ring.

• FPM sealing ring.

• Fluorocarbon rubber O-ring.

Viton - Registered Trademark

Viton is a registered trademark for specific fluoroelastomer materials.

Not every FKM/FPM O-ring is manufactured from Viton-branded material.

If genuine Viton is required for a particular application, the elastomer manufacturer and compound specification must be verified.

Properties of FKM/FPM Fluoroelastomer

Resistance to Engine and Gear Oils

FKM is commonly used in applications involving mineral oils and selected synthetic lubricants.

The exact compatibility depends on the lubricant formulation, chemical additives and operating temperature.

Resistance to Fuels

Many FKM compounds offer good resistance to gasoline, diesel fuel and selected hydrocarbon mixtures.

Compatibility with alcohol-containing fuels and specialised fuel additives must be evaluated for the specific compound.

Elevated Temperature Resistance

FKM is frequently selected for applications where conventional NBR rubber does not provide sufficient resistance to elevated temperatures.

However, a single temperature range cannot be applied to every FKM O-ring.

The permissible operating temperature depends on the compound formulation, operating medium and application.

Resistance to Ageing

Many FKM compounds provide favourable resistance to thermal ageing, ozone and atmospheric exposure.

These characteristics can be valuable in industrial sealing applications.

Chemical Resistance Limitations

FKM is not universally resistant to all chemicals.

Conventional FKM compounds may be unsuitable for contact with certain ketones, esters, amines and other aggressive substances.

Chemical compatibility must be confirmed before installation.

Applications of FKM/FPM O-Ring 15x3.5 mm

Fluoroelastomer O-rings are used in appropriately designed industrial connections and mechanical equipment.

Typical application categories include:

• Lubrication systems.

• Industrial pumps.

• Valves and fittings.

• Mechanical gearboxes.

• Oil circulation systems.

• Selected fuel systems.

• Hydraulic equipment.

• Industrial pipe fittings.

• Flange connections.

• Mechanical housings and covers.

These are general application categories. Suitability for a particular installation depends on groove design, operating pressure, temperature and fluid compatibility.

Lubrication Systems

FKM O-rings can provide effective sealing in systems containing compatible lubricating oils.

The material is often selected where resistance to oil and elevated temperatures is important.

Pumps and Valves

O-rings are used in suitable pump and valve assemblies to restrict fluid leakage between mating components.

Correct groove geometry and material compatibility are essential.

Fuel System Components

Selected FKM compounds are used in sealing applications involving compatible fuels.

Fuel composition, temperature and pressure must be verified before use.

Industrial Hydraulic Systems

FKM O-rings may be used in appropriately designed hydraulic assemblies when the material, hardness, dimensions and operating conditions meet the system requirements.

FKM vs NBR O-Rings - Material Comparison

When Should FKM Be Selected Instead of NBR?

FKM may be preferable when an O-ring is exposed to elevated temperatures or operating fluids requiring specific chemical resistance.

However, FKM is not automatically the best material for every application.

Low-temperature flexibility and compatibility with certain chemicals may favour alternative elastomers.

Can an NBR O-Ring Be Replaced with FKM?

Not automatically.

Even when the dimensions match, material compatibility, hardness, compression behaviour and operating conditions must be verified.

How to Select an FKM/FPM O-Ring 15x3.5 mm

Before purchasing, verify:

1. Nominal inside diameter of 15 mm.

2. Cross-sectional diameter of 3.5 mm.

3. FKM/FPM elastomer material.

4. Sealing groove dimensions.

5. Type of operating fluid.

6. Operating temperature.

7. Working pressure.

8. Static or dynamic sealing conditions.

9. Required elastomer hardness.

10. Dimensional tolerances and compression requirements.

Two O-rings with identical dimensions may differ in hardness, compound formulation and chemical resistance.

Why Is Elastomer Hardness Important?

Hardness affects the deformation and sealing behaviour of an O-ring.

The appropriate hardness depends on pressure, groove geometry, clearance and operating conditions.

The hardness of this specific 15x3.5 mm FKM O-ring has not been confirmed and should not be assumed.

Why Must Groove Dimensions Be Checked?

The groove determines how the O-ring is compressed during installation.

Insufficient compression may result in leakage, while excessive compression may accelerate wear or damage.

Correct groove design is essential for reliable sealing.

Installation of FKM/FPM O-Ring 15x3.5 mm

Surface Preparation

Before installation, clean the sealing groove and mating surfaces.

Remove dirt, metal particles and residues from previous seals.

Inspection of Sharp Edges

Sharp edges can cut or damage the O-ring during installation.

Use suitable protective tools or sleeves where necessary.

Avoid Twisting

Install the O-ring evenly without twisting or localised overstretching.

Twisting can interfere with correct seating and sealing performance.

Installation Lubrication

If installation lubrication is recommended, use a lubricant compatible with the specific FKM compound and operating fluid.

Correct Compression

Reliable sealing requires appropriate groove geometry and controlled compression.

Excessive compression can damage the seal, while insufficient compression may result in leakage.

Final Inspection

Before operating the equipment, check that the O-ring is correctly seated and has not been pinched or displaced.

Frequently Asked Questions - FKM/FPM Viton O-Ring 15x3.5 mm

What Are the Dimensions of an O-Ring 15x3.5 mm?

The nominal inside diameter is 15 mm, the cross-sectional diameter is 3.5 mm and the calculated nominal outside diameter is 22 mm.

Do FKM and FPM Refer to the Same Material?

Yes. Both designations refer to the general family of fluoroelastomer materials.

Is Every FKM O-Ring Made from Viton?

No. Viton is a registered trademark for specific fluoroelastomers. FKM materials are available from different manufacturers.

Is an FKM O-Ring Resistant to Engine Oil?

Many FKM compounds provide good resistance to engine oils. Compatibility must be confirmed for the specific lubricant and operating temperature.

Can an FKM O-Ring Be Used with Fuel?

Many FKM compounds are used in fuel-contact applications, but compatibility depends on fuel composition and compound formulation.

Is FKM More Heat-Resistant Than NBR?

Generally, yes, particularly at elevated temperatures. Exact temperature limits depend on the material specification.

Can an NBR O-Ring Be Replaced with an FKM O-Ring?

Not always. Chemical resistance, temperature, hardness and mechanical requirements must be checked.

What Is the Hardness of This FKM O-Ring 15x3.5 mm?

The hardness has not been specified. A value of 70 or 75 Shore A should not be assumed without confirmation.

Is This O-Ring Suitable for Hydraulic Applications?

It may be suitable for appropriately designed hydraulic systems when the elastomer material, hardness, dimensions and operating parameters meet the application requirements.

What Is the Outside Diameter of an O-Ring 15x3.5 mm?

The nominal outside diameter is 22 mm, calculated from the 15 mm inside diameter and twice the 3.5 mm cross-section.

Is FKM Suitable for High-Temperature Sealing?

FKM is commonly used in elevated-temperature applications, but the actual operating temperature limit must be verified for the specific compound.

FKM/FPM O-Ring 15x3.5 mm - Quick Technical Overview

FKM/FPM O-Ring 15x3.5 mm is a fluoroelastomer sealing ring with a nominal inside diameter of 15 mm, cross-sectional diameter of 3.5 mm and outside diameter of 22 mm. FKM materials are valued for resistance to many oils, fuels and elevated temperatures. Correct selection requires verification of hardness, chemical compatibility, groove dimensions and operating conditions.

FKM/FPM O-Rings at simmering.pl

At simmering.pl, we supply technical sealing components for industrial companies, machinery maintenance departments, mechanical workshops and B2B customers.

Our product range includes O-rings, rotary shaft oil seals, rolling bearings and other industrial replacement components.

Our warehouse and order processing operations are located in Lublin, Poland.

We supply customers throughout Poland and the European Union and offer worldwide shipping.

We also assist customers in identifying sealing components by dimensions, elastomer material and application requirements.