Product group:
XR X-Ring
FPM 70

Benefits of using the X-ring (compared with the O-ring): A high degree of stability for dynamic application, as the X-ring is not susceptible to rolling within the groove (twisting) due to its almost square cross-section. X-rings require a lower degree of radial pretensioning. This gives rise to less abrasion due to the lower contact pressures in play. It is possible for a lubricant reservoir to be created between the sealing lips. Optimised sealing effect due to superior distribution of pressure over the almost square cross-section. No adverse effect created by the mould-separation ridge as unlike the O-ring, this is not located at the outer diameter but between the actual sealing lips.

Other materials such as VMQ, EPDM and H-NBR are also available, on request.


Operational application limits

Temperature FKM:
-15 °C to +200 °C

Pressure (MPa):
dynamic, reciprocal movement to 5 MPa, to 20 MPa with back-up rings
static to 5 MPa, to 40 MPa with back-up rings

Speed (m/s):
reciprocal ≤ 0.5
rotary ≤ 2


X-rings are twin-action 4-lipped seals with an almost square cross-section profile. The X-rings achieves its sealing effect by being installed and compressed within an axial or radial installation housing. Under operating conditions, the pressure of the medium reinforces the sealing function.


Where possible, the installation housings for X-rings should be recessed as right angles and should be carefully processed to avoid any ridges, scratches and notches. To facilitate installation we can offer a variety of surface coatings, on request.


X-rings are comparable with the O-ring in their handling and use. For example, they are used for the radial and axial sealing of flanges, sleeves and covers (static application) and for sealing pistons and rod seals, rotating shafts and helical movements (dynamic). X-rings are used primarily for dynamic applications, as they require less pretensioning than O-rings and therefore give rise to less abrasion. They are very often used for quasi-static applications, such as adjustment and swivelling movements. They are also used for modern roller chains, such as motor bike chains, for example.