What it is

The crown retainer with cap is a fastening element made up of two main components, each with distinct functions yet working together as a single fastening system.
At the core of its operation is the well-known RPCO crown retainer, a fastening element designed to grip and firmly lock onto plain shafts of different diameters, stopping its own movement and consequently securing the component to be retained.
The second element is an actual cap, which performs a dual aesthetic and protective function. By concealing the fastening device, it enhances the overall appearance of the assembly while simultaneously protecting the joint area from external agents.

Technical features

The RPC family includes a wide range of retainers for shafts from 2 mm up to 25 mm in diameter, including intermediate sizes, all available in multiple shapes and several combinations of materials, surface coatings, and colors.
The classic version features a DC01 (EN10139) cap with nickel plating and a C67S carbon steel (EN10132-4) retainer, hardened and white zinc-plated 8 μm, with 72 hours of SSNT resistance.
The premium version is entirely made of stainless steel, highly corrosion-resistant, combining an AISI 304 cap with an AISI 301 retainer.
Other possible combinations are also available, including a nickel-plated cap with a raw steel retainer, a stainless steel cap with a zinc-plated retainer, or a nickel-plated cap with a stainless steel retainer.
Finally, all RPC retainers can be coated in the desired RAL color.
In addition to the traditional semi-spherical shape, the cap can also be edged or conical, depending on the required function and appearance. The edged cap adds an extra touch of elegance, while the conical version ensures deeper shaft penetration, increasing safety and stability.
One of RPC’s greatest strengths therefore lies in the endless customization possibilities and combinations between cap and retainer, according to specific aesthetic and functional requirements.

Applications

The fastening requirements addressed by RPC are typically found in assembly applications where the joint between shaft and retainer would otherwise remain too visible, compromising the overall aesthetics of the product — an issue solved by the flawless elegance of the cap.