NBR vs HNBR vs FKM Vacuum Suction Cups
NBR vs HNBR vs FKM Vacuum Suction Cups: How to Choose
Choosing between NBR, HNBR and FKM vacuum suction cups starts with understanding what the suction cup actually encounters: the workpiece surface, contact temperature, oils or chemicals, handling motion and production cycle.
NBR is a common choice for general industrial handling. HNBR can be considered when improved resistance to heat and aging is needed alongside suitable mechanical properties. FKM is often evaluated for applications involving elevated temperatures and particular oils, fuels or chemical media.
However, a material name alone does not define a suction cup’s performance. The compound formulation, hardness, sealing lip, cup geometry and operating conditions all influence the result.
For many applications, changing the material does not require a completely new suction cup design. EUROTECH can manufacture most existing suction cup designs using established compounds and existing molds, allowing customers to evaluate material alternatives without starting a new tooling project.
NBR, HNBR and FKM at a Glance
The following comparison provides a starting point for material selection. It does not replace the specifications of the individual suction cup or testing under actual operating conditions.
| Material | Common reasons to consider it | Important selection considerations |
|---|---|---|
| NBR — nitrile rubber | General industrial handling and applications involving compatible oils | Confirm temperature, chemical exposure and required service life |
| HNBR — hydrogenated nitrile rubber | Applications requiring improved heat and aging resistance compared with conventional NBR compounds | Check the exact compound, hardness, sealing behavior and operating conditions |
| FKM — fluoroelastomer | Elevated temperatures and exposure to particular oils, fuels or chemicals | Verify compatibility with the actual medium; FKM is not resistant to every chemical |
For a broader comparison that also includes silicone, polyurethane and other materials, see our vacuum suction cup material guide.
When Is NBR the Right Choice?
NBR suction cups are widely used in industrial handling because they offer a practical balance of mechanical properties, oil resistance and cost.
Typical applications include handling glass, sheet metal, plastic components and other workpieces where the surface can form a reliable vacuum seal.
NBR may remain the appropriate choice when:
- The operating temperature is within the specified limits of the cup.
- Oils, lubricants and cleaning agents are compatible with the compound.
- The sealing lip maintains its flexibility and shape.
- Service life is acceptable for the production process.
- Surface contact does not create unacceptable marks or contamination.
A higher-cost material is not automatically necessary when a suction cup wears out. A damaged lip may result from dragging across the workpiece, excessive compression, sharp edges or incorrect alignment.
Before changing materials, check whether the problem comes from the rubber itself or from the way the suction cup is being used. Learn how to troubleshoot swelling, hardening and cracking in vacuum suction cups to identify what should be checked before selecting a replacement.
When Should You Consider HNBR?
HNBR is produced by hydrogenating nitrile rubber. It is commonly considered when an application requires improved resistance to heat, oxidation and ozone compared with conventional NBR compounds.
For vacuum handling, HNBR may be worth evaluating when a cup repeatedly contacts warm or hot workpieces, or when the existing NBR compound loses flexibility too quickly under the operating conditions.
Potential applications include:
- Handling heated plastic components.
- Transferring industrial parts exposed to compatible oils.
- Repeated handling where heat and aging affect cup performance.
- Applications requiring a balance of thermal resistance and mechanical durability.
The decision should be based on the specific compound and suction cup design. HNBR is not automatically the best option for every hot surface, chemical exposure or high-cycle application.
It should also not be assumed that every HNBR suction cup is non-marking. Surface results depend on the formulation, workpiece, temperature, contact pressure and cleanliness.
When Should You Consider FKM?
FKM suction cups are often evaluated for demanding environments involving elevated temperatures or contact with particular oils, fuels and chemical media.
A possible reason to investigate FKM is a recurring material compatibility problem: for example, the existing cup changes dimensions or loses its sealing properties after exposure to a process fluid.
However, “chemical-resistant” does not mean universally resistant.
Standard FKM compounds can have limitations with media such as certain ketones and esters. A general description such as “solvent,” “cleaner” or “oil” is therefore not enough to select a material.
Useful information includes:
- The exact product or chemical name.
- Concentration or mixture composition.
- Operating temperature.
- Frequency and duration of contact.
- Whether exposure involves splashes, residue or prolonged contact.
FKM should be selected because its properties match the application, rather than simply because it is a more expensive material.
For injection-molded components and other heated plastic workpieces, read our guide to suction cups for hot plastic parts. It explains how contact temperature, cycle time, cup geometry and downstream surface requirements affect selection.
Why the Compound Matters as Much as the Polymer
Two suction cups described as NBR may behave differently.
Hardness, fillers, additives, curing systems and manufacturing conditions can influence flexibility, aging, wear and contact behavior. The same principle applies to HNBR and FKM.
This is why general material tables are useful for screening options but cannot provide a complete product specification.
In particular, a temperature range published for an elastomer or an O-ring should not automatically be applied to a finished suction cup. The cup may include a bonded insert, backing plate or other components, and it operates through repeated deformation and contact.
Use the specifications of the actual cup and compound when making the final selection.
Six Questions to Ask Before Changing Materials
1. What is the actual contact temperature?
Measure or establish the temperature at the point where the suction cup touches the workpiece. Furnace, mold or process settings may differ considerably from the contact temperature.
2. How long does contact last?
Brief contact followed by cooling is different from prolonged contact. Repeated cycles may also cause the cup to warm up during production.
3. Which substances contact the cup?
Include lubricants, coolants, cleaning agents, release agents and residues on the workpiece—not only the main process fluid.
4. What is the surface like?
A smooth, flat surface presents different sealing requirements from a curved, textured or slightly uneven surface. Material flexibility must suit the geometry.
5. How does the workpiece move?
Consider lifting direction, acceleration, lateral forces and the possibility of sliding. Material changes can affect friction and deformation even when the nominal cup dimensions remain the same.
6. What happens after handling?
Painting, printing, bonding or other surface-sensitive processes may impose additional requirements. Check both visible marks and downstream process compatibility.
For a complete overview of size, shape and operating conditions, use our vacuum suction cup selection guide.
Can You Change the Material Without a New Mold?
For most EUROTECH suction cup designs, alternative material versions can be produced using existing molds and established compounds.
The available design range includes flat suction cup families such as 200 PK, 280 PK, R, RL, A, B and CO, as well as oval types.
This gives customers a practical route to evaluate a different material while working from an existing product design.
| Existing product range | Information to confirm |
|---|---|
| 200 PK and 280 PK | Material requirement, dimensions, mounting and operating conditions |
| R, RL, A, B and CO families | Exact model, size, hardness, connection and handling task |
| Oval suction cups | Available contact area, dimensions, orientation and material requirement |
Existing tooling can remove the need for a new mold, but it does not remove the need to confirm the finished product’s suitability. Changing the material may affect sealing, deformation, friction and dimensional behavior.
Explore our flat vacuum suction cups and oval vacuum suction cups, or learn more about custom suction cups and material options.
How to Validate a Material Change
A useful comparison keeps the operating conditions as consistent as possible.
Record the cup model, material, vacuum level, workpiece, temperature, cycle time and handling motion. Then evaluate:
- Fit and mounting.
- Vacuum build-up and leakage.
- Sealing lip deformation.
- Resistance to slipping during movement.
- Visible surface marks or residue.
- Condition after repeated cycles.
- Results of any subsequent painting, printing or bonding.
Compare the new material with the existing version under documented conditions. Do not assume that the original holding-force figures or service life remain unchanged after a material substitution.
Frequently Asked Questions
Is HNBR always better than NBR?
No. HNBR may provide useful improvements in particular operating conditions, but NBR can remain the more appropriate choice when it already meets the application requirements.
Does changing to FKM increase lifting capacity?
Not automatically. Vacuum holding performance depends on effective area, pressure difference, sealing, deformation and the forces acting during handling. A material change requires application-specific verification.
Are HNBR and FKM suction cups non-marking?
The material family alone cannot guarantee a non-marking result. The compound and its interaction with the actual workpiece must be evaluated.
Can EUROTECH produce special-material cups without new tooling?
Most existing EUROTECH suction cup designs can be evaluated for production using established compounds and existing molds. The exact material version, specifications, quantity and lead time are confirmed for the selected product.
Discuss Your Suction Cup Material Requirements
If you are considering a change from NBR to HNBR or FKM, send EUROTECH the existing cup model or dimensions, workpiece photos, contact temperature and details of any oils or chemicals involved.
We can review the available material options across our existing product range and identify suitable candidates for testing.
Contact EUROTECH for a suction cup material recommendation.