RIPP LOCK®

Verbus RIPP screws have been around for many years. They are based on a principle used millions of times over that is both secure and non-damaging to surfaces. 

The Junker vibration test shows that RIPP LOCK® reliably secures screw connections, even under dynamic transverse stress. The system maintains the preload force significantly better than other locking elements, therefore providing greater protection against connections working loose. 

A screw connection is considered secure if it retains 80% of the applied, required preload force. Every element designed to act as a locking device must meet this specification. Our RIPP LOCK® satisfies the requirements applicable to locking devices. 

Many screw connections are safety-critical, for example those in pumps, construction or agricultural machinery, or lift shafts. Even if the required preload force can be applied, the clamping length is sufficiently long and there are few joints, dynamic loads (especially those acting transverse to the screw axis) still significantly increase the risk of the connection failing.

That's why many of our customers put their trust in RIPP LOCK®.

RIPP LOCK® not only provides reliable locking, but also ensures clearly defined clamping forces thanks to its defined coefficients of friction. The high-quality surface also has a positive effect on friction. This means that the tightening torques determined in accordance with VDI 2230 (and as such also the required clamping forces) can be applied to almost all applications, including light metals with high coefficients of friction.

RIPP LOCK® is gentle on delicate surfaces such as those that are galvanised, chrome-plated or painted. The images show components after being fastened with RIPP LOCK® and a spring washer. Distinct differences can be seen on the surfaces. 

Our client, Klaas Alu-Kranbau GmbH, uses RIPP LOCK® self-locking washers, for example, not only due to their excellent locking performance. Surface compatibility and consequently corrosion resistance are also critical in this application. 

The steel grade with hardness 400–500 HV has a zinc flake coating with certified corrosion resistance: 480 hours of exposure to red rust in a salt spray test. Furthermore, RIPP LOCK® self-locking washers are also available in A4 stainless steel with hardness 800 HV. 

Many fasteners with a zinc-lamella coating contain PFAS to control friction coefficients and ensure corrosion protection. With the EU planning a comprehensive ban on PFAS, many suppliers are turning to PFAS-free alternatives. RIPP LOCK® has already adopted this approach and offers a PFAS-free solution – a clear advantage over competitor products with topcoats containing PFAS. 

The outer diameter of the RIPP LOCK® washer corresponds to the DIN 125 specification. It can be readily integrated into existing assemblies. As such, design changes are superfluous. 

In order for the radial ribs of the RIPP LOCK® washer to perform their locking function, they must bite into the mating surface of the screw head or nut when tightened – without undergoing any plastic deformation themselves. This means the self-locking washer must be at least as hard as the screw's mating surface. Thanks to the high hardness of the washers, RIPP LOCK® self-locking washers can be used up to strength class 12.9.

The locking function of RIPP LOCK® is based solely on a mechanical form fit. The radial ribs physically bite into the mating surface, creating geometric interlocking (or ribbing) between the washer and mating surface.

This form locking works regardless of the presence of oil or grease.

No chemical reaction needs time to take effect. The form fit is established through mechanical deformation when the screw connection is tightened. 

Slotted holes facilitate adjustment and positioning, but make it more difficult to permanently secure the connection. With RIPP LOCK®, this dilemma becomes a thing of the past: the ribs hold the screw head securely in place, maintain its position and ensure a constant preload force. 

There's not always enough space for a RIPP LOCK® self-locking washer. Some connections are made with countersunk cylinder head screws. Once again, we have the ideal solution: the RIPP LOCK® self-locking washer with reduced outer diameter.