pre-applied sealing coatings
purpose of a pre-applied sealing coating
"Tight" describes the complete prevention of the penetration and permeation of a medium into the screw connection.
How a sealing pre-applied coating for fasteners works
in sealant must basically fulfill three requirements.
- Adhesion of the coating > than the applied pressure
- Cohesion of the coating > than the applied pressure
- Coating surface or length must be adapted to the application
Sealing in the threads
The sealing effect is achieved by filling the gap between the external and internal thread with the coating material.
The filling quantity of the coating must match the tolerances and the manufacturing method of the thread. At least four fully coated threads must be installed in an overlapping position. Movements against the mounting direction should be avoided or minimized.
Sealing under the head
The recommended product layer thickness is approx. 0.05 mm to 0.2 mm. The sealing effect is achieved by pressing the coating into the surface roughness of the parts to be joined. The metal-to-metal contact prevents settling. The coating material is partially pressed out of the gap and forms a ring around the screw head.
Note: As there is no internationally valid standard for gaskets, these instructions must be applied separately for the individual applications.
Sealing products
