19-09-2023 | By Northern Connectors

Connectors often have to endure a range of elements, from dust and moisture to high or low temperatures and pressures. Whether it’s an outdoor environment or an indoor industrial environment, connectors must be engineered to the appropriate level of ingress protection.

While they don’t directly address the product’s temperature and pressure limits, ingress protection (IP) ratings provide information about the product’s level of resistance against solids and liquids.

The highest IP ratings promise complete protection against dust ingress and protection against water ingress under certain conditions, which are usually specified by the manufacturer.

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Decoding IP Ratings: Dust and Water Resistance 

The IP code indicates a device's protection against water and dust. For example, an IP67-rated device is dust-resistant and can be submerged in 1 meter of freshwater for up to 30 minutes. This classification system, also known as the ingress protection code, is established under the international standard IEC 60529 by the International Electrotechnical Commission (IEC).

After all, there’s a difference between water-resistant and waterproof – splashproof doesn’t mean immersible, and getting this wrong could be a costly mistake.

IP67 and IP68 are among the top IP ratings. IP67 connectors can be submerged up to 1 meter for 30 minutes, while IP68 connectors can be immersed deeper than 1 meter for extended durations, with specifics detailed by the manufacturer.

This blog will explain the different levels of watertightness to help you choose the connector with the right IP rating for your application.

IP Code: Protection Levels Explained

The IP code defines protection levels against solids (0 for no protection to 6 for dust-tight) and liquids (0 for no protection against water to 9 for protection against high-pressure, high-temperature sprays). It's essential to note that the ratings for water ingress are not cumulative beyond IPX6. For instance, a device compliant with IPX7 (covering water immersion) might not necessarily comply with IPX5 or IPX6 (covering exposure to water jets).

To better understand the significance of IP ratings, it's essential to decode the IP code. The first digit indicates the level of protection the enclosure provides against solids, such as dust. The second digit, on the other hand, signifies the protection level against liquids, primarily water.

IPX Codes Explanation Chart

By Mahesh PathakI, IPX Codes Explanation Chart, CC BY-SA 4.0, Link

Origins of the IP Code

In the original IEC 60529 standard from 1976, the letters IP were used without a clear explanation, referred to as "characteristic letters". In subsequent editions of the standard, IP was clarified to represent "international protection" in both French and English. The abbreviation might be a combination of the English word "ingress" and the French word "pénétration" both signifying ingress. However, the exact origin would require a deep dive into the 1970s standardisation, a challenging task since many experts from that era are likely retired or no longer alive.

Deciphering the IP Code: Dust and Water Ratings

The level of protection against water ingress can vary, which is why manufacturers prefer the term ‘watertight’ – as their products are not infinitely waterproof but can resist it for some time.

It's essential to understand that the IP rating system, established by the International Electrotechnical Commission (IEC), serves as a ruggedness scale. This system provides a clear indication of a device's ability to withstand environmental factors, particularly water and dust. In fact, studies have shown that up to 20% of all phone damage results from immersion or contact with liquids. Hence, understanding these ratings becomes crucial for both manufacturers and consumers. 

IP67 Connectors: Dust-Proof and Temporary Water Immersion

As the first letter of the rating applies to solids, the 6 in IP67 is the highest rating of dust protection, completely preventing dust and other particles from getting inside the equipment.

The second letter applies to water ingress, and 7 is the lowest rating that offers a level of water tightness – a rating of 6, in this case, means the product would be protected against jets of water but cannot actually be submerged in water without ingress occurring.

IP67 generally means that the product can withstand immersion in water at depths of up to 1 metre for up to 30 minutes, with no harmful effects from limited ingress.

This is suitable for brief and temporary submersion but not for a scenario where connections would have to run underwater or may be immersed in water for longer periods of time.

If your application doesn’t require immersion, but there is a potential risk of this occurring, then IP67 products offer peace of mind that ingress won’t immediately occur.

However, if your application requires connectors that can withstand immersion for longer than 30 minutes at depths greater than 1 metre, an IP67 rating will not be sufficient.

IP68 Connectors: Dust-Proof and Prolonged Water Immersion

The next level up has the same top rating of 6 for dust protection, meaning IP68 products are also completely sealed against ingress from dust and particulates.

The difference is that IP68 has a higher water ingress rating, which means a product with this rating can be immersed in water deeper than 1 metre for a continuous period.

The manufacturer will test and specify the maximum depths and length of time that the ingress protection will hold depending on the product’s intended use, but IP68 typically applies between 1–2 metres deep for longer than 30 minutes.

In any case, harmful levels of water ingress should not be possible when immersed continuously under the conditions specified by the manufacturer, which will be more severe than IP67’s limits.

Determinants of IP68 Connector Effectiveness

The manufacturer may also specify factors such as temperature fluctuation and flow rate, which may affect the duration of effective ingress protection.

If you require connectors that can withstand high levels of pressure in addition to immersion in water for limited periods, then you may need to upgrade from IP68 to IP69K.

This is the highest possible IP rating for watertightness, promising protection against ingress from high-pressure and high-temperature jets, which are normally used in industrial cleaning.

It's worth noting that while IP67 and IP68 are among the most sought-after ratings, there are other IP ratings available, each designed for specific conditions. For instance, IP66-rated connectors are dust-tight and include a vacuum seal, ensuring protection against particulates and any airflow. They are also waterproof, safeguarding against direct high-pressure jets. Understanding the nuances of each IP rating can significantly influence the success and longevity of your project. 

Choosing Between IP67 and IP68 Connectors

They are both suitable for environments with risks of spraying or splashing, but your choice should be guided by the manufacturer-set limitations for actual immersion.

Where possible, these should include details of the product’s pressure and temperature resistance, as well as corrosion resistance, as most IP ratings apply to freshwater.

It’s best to treat an IP rating as an indication rather than a guarantee, as they don’t account for all scenarios, and opt for a higher rating if you aren’t sure whether a lower rating will be sufficient.

It’s also important to remember that some parts only achieve the assigned IP rating when installed in a particular way, usually requiring all parts to have the same IP rating or higher.

If necessary, you can ask the experts – Northern Connectors are trusted UK suppliers of a selection of watertight connectors and accessories from leading international manufacturers and would be happy to offer guidance before you place an order.

In Summary

IP ratings play a crucial role in determining the resilience of connectors against environmental factors like dust and water. Understanding the nuances between ratings like IP67 and IP68 can make a significant difference in the longevity and efficiency of your equipment. Always consult with experts and manufacturers to ensure you're making the right choice for your specific needs.


  1. Northern Connectors - Characteristics
  2. Electropages - IP67 vs. IP68: IP Codes Demystified
  3. ANSI Blog - IP Code Rating for Smartphone Water Protection
  4. Wikipedia - IP Code

By Northern Connectors

Northern Connectors is renowned for its diverse catalogue of industrial connectors, each tailored to meet specific requirements. Their range encompasses connectors with IP ratings from IP20, which offers protection against fingers or other objects smaller than 80mm in length and 12mm in diameter, to IP69K, which promises complete protection against dust and water, even under high water pressure or steam cleaning conditions. This wide array ensures that engineers across various industries can find connectors that precisely match their application needs.