Screws are among the most important connection types. More than 60 years ago, we made their protection our mission. With numerous patents, we are able to reliably protect virtually all screw connections from corrosion and damage.

For our customers this means maximum lifespan and reliability, construction quality and the reduction of maintenance costs.


The patented RADOLID® System


All RADOLID protective caps have a sealing lip that seals the system outwardly. It is fitted on the lower outer edge of the cap and adapts to the surface during fitting.


RADOLID protective caps have a circular cross section in every case. This allows us to minimise residual stress generated during the production process so that the caps do not tear or split, even where large nut and bolt head tolerances are involved.


RADOLID type SW, DSW, ESW, HSW and TSW locking caps have a locking edge on the lower inner edge. This engages under the chamfer of the nut, ensuring a firm, secure connection of the protective cap.


The RADOLID protective cap groove forms a circumferential protective chamber between the locking edge and sealing lip. Penetrating moisture is collected and distributed here, thus preventing it from penetrating directly into the interior of the cap.

RADOLID® Lifetime-Warranty

We guarantee a service life of up to 15 years for our standard SW, HSW, TSW, B and BM series, depending on the application. Please contact us to select the right cap with an optimum service life for your application.