We define electrical connector fretting wear as wear that is caused by small, repetitive, almost micro-motion movements in an apparently stationary connector but is the subject external mechanical excitation (e.g. a combustion engine). Thermo cycling is another type of wear that is often associated with fretting but obviously the frequencies involved are nowhere near as high.

Fretting corrosion is defined as the combination of fretting wear and corrosion (mainly due to oxidation). Fretting wear and oxidation can affect most metal types but tin-plated electrical contacts are particularly susceptible to fretting problems. Tin is quite soft and a thin oxide layer can be quickly formed. When the oxide layer is broken, the fragments can be pushed/pressed into the tin and the ‘downward spiral’ of wear begins. The fragments will accumulate and cause an increase in electrical resistance, sometimes with minimal change in appearance to the contact surface.

If fretting corrosion occurs in your electrical connectors, it can prove very problematic.

Electrical terminals sometimes only actually conduct over a relatively small percent of their total surface area. It is the asperities of the contact surfaces across which the current is passing across. In addition to the potential for fretting corrosion, the space around the asperities is also subject to oxidative corrosion. Connector lubricants fill in the space between the asperities to protect the contact metal.

There are numerous advantages gained by lubricating electrical connectors – guarding against oxidation, fretting corrosion, contact wear and extending connector life. A thin film of lubricant can also reduce mating force by as much as 80 percent, which is an important factor in connector assembly. For gold-plated connectors an effective lubricant reduces the potential for noble metal wear during mating and separation.

A dielectric connector lubricant will not cause increased circuit impedance and will not cause cause connectivity problems in multi-pin connectors as it is not thermally or electrically conductive (up to a voltage limit). The connector grease will environmentally seal the contact surface area and not allow harmful gases or moisture/water to penetrate a connector and cause circuit problems in your device. A synthetic connector grease will also last the functional life of your connector and actually extend the component life.

Why find out more about How Electrical Connector Lubricants Work.

The below images show results from some benchmarking tests we conducted ‘dry’ vs terminals treated with our core range of connector grease.

Now find out which connector grease is right for you via the a Choosing a Connector Lubricant article or look at our other fretting related articles.

Connector lubricants can be purchased in small containers/small volumes at our online shop.

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