The first digit: solids and dust
| Digit | Protection against |
|---|---|
| 0 | not protected |
| 1 | solid objects of 50 mm and larger (back of the hand) |
| 2 | 12.5 mm and larger (fingers) |
| 3 | 2.5 mm and larger (tools, thick wires) |
| 4 | 1.0 mm and larger (thin wires) |
| 5 | dust-protected: some dust may enter, but not enough to disturb operation or safety |
| 6 | dust-tight: no dust enters |
The second digit: water
| Digit | Protection against |
|---|---|
| 0 | not protected |
| 1 and 2 | vertically dripping water; dripping water with the enclosure tilted up to 15° |
| 3 and 4 | spraying water; splashing water from any direction |
| 5 | water jets from a 6.3 mm nozzle, any direction |
| 6 | powerful water jets from a 12.5 mm nozzle |
| 7 | temporary immersion, typically up to 1 m for 30 minutes |
| 8 | continuous immersion under conditions stated by the maker, more severe than 7 |
| 9 | high-pressure, high-temperature water jets (added to IEC 60529); IPX9K is the road-vehicle version in ISO 20653 |
An X in place of a digit means that test was not specified, so IPX4 says nothing about dust.
IP65, IP66 or IP67?
All three are dust-tight. The difference is the water test: IP65 withstands water jets, IP66 powerful jets, IP67 short immersion. Immersion and jets are different tests, so an IP67 product has not necessarily passed the jet test. A product tested for both is marked with both codes, for example IP66/IP67. For outdoor fittings exposed to rain and washing, IP66 is often the more useful figure; IP67 matters where the item can sit in water, such as pits, low junction boxes or ground-level fittings.
IK codes for impact (IEC 62262)
IP says nothing about mechanical strength. The IK code from IEC 62262 rates impact resistance, from IK00 to IK10. Common values: IK07 = 2 J, IK08 = 5 J, IK09 = 10 J, IK10 = 20 J. Choose IK08 or higher for fittings and enclosures that forklifts, tools or vandalism can hit, such as low-mounted lights, loading bays and public areas.
Choosing for site conditions
- Indoor plant rooms, clean and dry: IP20 to IP4X equipment inside a suitable panel is often enough.
- Desert dust and sandstorms: choose a first digit of 6 (IP6X). Fine sand gets into IP5X equipment over time.
- Outdoor, rain and sun: IP65 or IP66, with UV-resistant materials and gaskets.
- Wash-down areas (food plants, vehicle washing): IP66 at least; IP69 or IPX9K where high-pressure hot cleaning is used.
- Pits and flooding risk: IP67, or IP68 to the maker's stated depth and time.
The rating only holds when installed correctly
An IP66 enclosure becomes IP54 or worse if you drill a hole and fit a lower-rated gland, leave out a gasket, or mount it with the cable entries facing up. Use glands, plugs and breathers with at least the same rating, tighten covers as the maker instructs, and in hot climates think about condensation: a sealed box that heats and cools every day can collect water inside, so a rated drain or breather may help.
What to send us for a quotation
The product type, the IP and IK rating your specification asks for, where it will be installed (indoor, outdoor, wash-down, pit), the size and material, and the cable entries needed. We quote the enclosure or fitting with matching glands, plugs and accessories so the whole assembly keeps its rating.
Common questions
Is IP67 better than IP66?
Not necessarily. IP67 is a short immersion test and IP66 is a powerful jet test. They are different, so a product needed for both should be marked IP66/IP67.
What does the X in IPX4 mean?
It means the solids test was not specified. IPX4 only tells you the product resists splashing water from any direction.
Which IP rating is best for desert dust?
Choose dust-tight equipment with a first digit of 6, such as IP65 or IP66, and keep the same rating on every gland and cover.
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This guide is general information. Final selection must follow the project design, the applicable standards and the maker's data.