90 Shore A Hardness Characteristics
Higher Resistance to Compression Deformation
90 Shore A FKM compounds provide higher resistance against compression set and dimensional change under continuous sealing pressure.
Extrusion Resistance
The harder compound helps reduce extrusion risk when the seal is exposed to higher pressure gaps or mechanical loads.
Mechanical Stability
The increased hardness improves resistance to wear, deformation, and repeated assembly conditions.
Quality Control
- Dimensional Inspection
Finished O-rings are measured for critical dimensions, including inside diameter (ID), outside diameter (OD), and cross-section (CS). Dimensional checks ensure the seal matches the specified groove design and installation requirements.
- Hardness Testing
The rubber hardness is tested according to the Shore A scale to verify that the FKM compound reaches the required 90 Shore A specification. Consistent hardness helps maintain predictable compression behavior and resistance to deformation.
- Material Testing
FKM rubber compounds are inspected before production to verify material consistency and suitability for the intended sealing environment. Material checks help confirm properties required for oil, fuel, chemical, and temperature exposure.
FAQ
What is the difference between 70 Shore A and 90 Shore A FKM O Rings?
The main difference is hardness. 70 Shore A compounds provide greater flexibility and are commonly used for general sealing applications, while 90 Shore A compounds provide higher resistance to deformation and are selected for more demanding sealing conditions.
Are 90 Shore A FKM O Rings suitable for high-pressure applications?
They can be used in applications where higher hardness is required to reduce extrusion and deformation risks. The actual pressure capability depends on factors such as groove design, clearance gap, temperature, and sealing conditions.
What fluids can FKM O Rings handle?
FKM is commonly selected for contact with petroleum-based oils, fuels, lubricants, hydraulic fluids, and many chemical media. Material compatibility should be confirmed according to the specific fluid and operating environment.
