Choosing a connector lubricant

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, an important factor in connector assembly. Grease rather than oil is generally preferred due to the obvious ‘stay in place’ ability of a grease compared to an oil.

A note about the general chemistry of the connector greases available….If you are unfamiliar with connector grease/lubricants, these are not ‘grease’ in the typical sense, if you have only really used cheap grease in the past, i.e. these are not mineral based, brown sludges that are mass produced. Synthetic connector lubricants are precisely engineered products of which there are many types to cope with the varied challenges in real world applications – from domestic type applications, to automotive, aviation, high temperature, extreme environments and even satellite applications where low outgassing lubricants are required.

The two most common reasons for using a connector lubricant is to prevent water ingress and/or stop fretting corrosion. Unsure about the topic of fretting corrosion? Look out for our Understanding Fretting Corrosion article that is coming soon.

For complex electronic connectors with dozens or even hundreds of pins, or for automotive connectors that are in hard-to-reach places, a low insertion force makes assembly more efficient and ensures solid connections. For gold-plated connectors an effective lubricant reduces the potential for noble metal wear/damage during mating and separation.

The products discussed below are suitable for electronic/electrical applications and data connections – both digital and analogue.

A guard against corrosion – Lubricants guard against oxidation and the effects of harsh environments. With gold-plated connectors this means protection against substrate corrosion. Thin gold plating can be microscopically porous and a thin film of lubricant can seal the pores, prevent substrate attack and assure low contact resistance. Over the years we have noticed manufacturers using gold plated contacts to deal with the threat of fretting corrosion but OEMs can end up dealing with dealing with fretting despite using gold as enough of the gold coating is scratched away during initial mating, negating the use of gold in the first place….especially where the thickness of the gold plating is really probably too thin in the first place.

A special mention about preventing fretting corrosion in separable connectors – this is obviously a key ability of a quality connector lubricant if you are reading this due to suspected fretting issues. In addition to atmospheric corrosion, tin/lead connectors can be subject to ‘fretting corrosion’ which is the result of low amplitude vibration caused by thermal expansion and contraction and/or nearby motion from fans, motors/engines or anything else that causes the connector to vibrate. The process of fretting corrosion causes micro abrasion of the contact surfaces and continually exposes fresh layers of the metal surface to oxidation. A lubricant film minimises metal to metal contact during vibration, protecting the connector from metal wear. Take a look at the supporting information sheet Connector Grease – Facts & Myths (scroll down the page) to help understand the facts & myths associated with connector lubrication.

The products discussed further down this page are suitable for electronic/electrical applications and data connections – both digital and analogue. So let’s summarise the main reasons for choosing an electrical/electronic connector lubricant, which will mostly be one or more of the following reasons:

• Protect against water ingress
• Prevent fretting corrosion
• Reduce contact wear if separable connects are unmated and re-mated repeatedly
• Extend the functional life of the connector
• Reduce the insertion force required to mate the connector
• Guarding against oxidation

There are four core products from the connector grease range, manufactured by our partners at Nye Lubricants. More products are available and where relevant Nye will custom formulate a product for your requirements. These four products account for most of our sales and so together would cover about 90% of applications that customers contact us about. The products below utilise different chemistries due to the variety of demands from the market place – no one formula can tick all the boxes so it is important to pick out the grease that is best suited for your connector application.

Tribosyn 330 is our most cost effective connector grease and will deal with 95% of our customer requests…

Tribosyn 330

• Recommended temperature range of -40 to 135°C
• The ‘go to’ connector lubricant for the majority of customers – widely used and the most cost effective product.
• The best dielectric connector grease for resistance to water and salt water – the product in this list that has the best water resistance properties.
• Tribosyn 330 has an excellent pedigree, especially in the automotive market where it is used by most of the automotive manufacturers around the world. An effective solution against fretting corrosion, oxidation and general contact wear.
• Tribosyn 330 is compatible with all metals including gold and silver. Most commonly used on tin plated terminals.
• 330 is clear/translucent in appearance and so can be hard to see in thin layers – it has a UV tracer/dye included in the formula to aid visibility in small amounts.
• Compatible with most plastics and elastomers/rubbers.

Small amounts/containers of Tribosyn 330 can be purchased at our online shop (opens in new tab).

If you have any connectors operating in extreme environment such as exposure to hazardous gases or extreme temperatures, why not get in contact to discuss your connector grease requirements? We can help you determine the most suitable product for your connector/contact problem. We have a network of contacts around the world and can help with some local engineering assistance.

An important note about potential compatibility issues between grease and plastics/rubbers. This issue here is the same for any use of lubricants/grease no matter what the application or who the lubricant manufacturer is; some oils/grease can make plastics and/or rubbers swell, crack or cause discolouration. Readers of this article should not be alarmed but due care should be taken so we recommend you read our article on Lubricant and Plastic Compatibility Issues.

Why not take a look at our article about the ‘Facts & Myths of Electrical Connector Lubricants‘…some interesting stuff on there! Such as:

The reader might have noticed that we do not recommend any silicone based grease for use on electrical connectors. Why? In short, silicones can polymerise into hard, brittle material that can cause electrical problems. If you would like to read further about this issue, take a look at the article Not Recommended-Silicone lubricant use on electrical connectors.