Datasheet
© Freudenberg Simrit GmbH & Co. KG | Technical Manual 2007552
Technical Principles | O-Rings and Static Seals
Static Sealing
The sealing effect of the ISC O-Ring is attributable to 
its axial or radial change of shape of its cross-section 
once installed. This change of shape is achieved by 
a corresponding designing of the installation space. 
The resultant reactive force provides the seal with 
the necessary contact pressure, which is additionally 
 supported by pressure from the medium.
ISC O-Rings can be used for the sealing of stationary 
machine components, i.e. for static sealing. With the 
proper fitting and the correct choice of material, pres-
sures of up to 1000 bar and more can be sealed. The 
dimensions of the installation space depend on the 
binding strength used and the respective application 
conditions. The groove dimensions reveal, depending 
on the ring thickness and application situation, a mean 
compression under pressure of 15% to 30%. With pul-
sating pressures the hardness of the ISC O-Ring material 
should not be less than 80 Shore A.
Selection of the material hardness is dependent on the 
prevailing pressures and the specified tolerances
(gap widths); → Fig. 8 and Fig. 9.
Note: the specified groove dimensions are recommen-
dation and are taken from the nominal dimensions.
In any case a calculation of tolerances (minimum/ 
maximum) must be performed.
We recommend the following gradation:
Operating pressure Material hardness
≤16 MPa 70 Shore A
>16 MPa 90 Shore A
Tbl. 1
p
Un-pressurised
Deformed under pressure
Fig. 1










