An IP (Ingress Protection) rating from IEC 60529 is two digits: the first is protection against solids and dust (0–6), the second is protection against water (0–9). So IP65 means dust-tight and protected against water jets; IP67 means dust-tight and protected against temporary immersion. The number you need comes from where the enclosure lives — but the rating is only real if the whole box build is sealed for it: the gasket, the cable glands, the connectors, the display window, and the seams all have to hold, not just the enclosure shell. A box marked “IP65 enclosure” can still let water in through an unsealed gland.
This guide explains what each digit means, what the common ratings actually survive, the IP65-vs-IP67 question, how the rating is achieved and verified in a real box build, and what to put on your drawing.
What the two digits mean
Read an IP rating as IP[solids][water]. Each digit is a defined test level under IEC 60529, not a marketing scale:
| Digit | First digit — solids/dust | Second digit — water |
|---|---|---|
| 0 | No protection | No protection |
| 1 | Objects ≥ 50 mm (back of hand) | Dripping water |
| 2 | Objects ≥ 12.5 mm (finger) | Dripping at 15° tilt |
| 3 | Objects ≥ 2.5 mm (tools) | Spraying water |
| 4 | Objects ≥ 1 mm (wires) | Splashing water |
| 5 | Dust-protected (limited ingress, no harm) | Water jets |
| 6 | Dust-tight (no ingress) | Powerful water jets |
| 7 | — | Temporary immersion (up to 1 m, 30 min) |
| 8 | — | Continuous immersion (beyond 1 m, as specified) |
| 9 / 9K | — | High-pressure, high-temperature jets (steam cleaning) |
A digit can be replaced by X when that protection is not specified — for example IPX7 rates water immersion without stating a solids level. The higher water digits are not a simple ladder: a device rated IP67 (immersion) is not automatically IP65 (jets), because immersion and directed jets are different tests, so a spec that needs both states them together, such as IP66/IP67.
Common ratings for box builds — and what each survives
- IP54 — dust-protected and splash-protected. Fine for indoor equipment away from direct water.
- IP65 — dust-tight and protected against water jets from any direction. The workhorse for outdoor and washdown-adjacent enclosures. Target this when rain, hose spray, or wet cleaning is the threat.
- IP66 — dust-tight and protected against powerful water jets. Heavier washdown and marine-adjacent duty.
- IP67 — dust-tight and survives temporary immersion (up to 1 m for 30 minutes). Choose this when the box may be briefly submerged or flooded, not just sprayed.
- IP68 — dust-tight and rated for continuous immersion at a depth and duration the manufacturer specifies. For genuinely submerged applications.
- IP69K — dust-tight and rated for high-pressure, high-temperature steam cleaning. Common in food, pharma, and heavy vehicle equipment.
IP65 vs IP67: the question people actually ask
IP65 and IP67 share the first digit — both are dust-tight — and differ in the water test. IP65 is protection against water jets; IP67 is protection against temporary immersion. They answer different threats: IP65 for rain, hose-down, and washdown spray; IP67 for a box that could be briefly submerged or sit in standing water. IP67 is not “more IP65” — passing an immersion test does not guarantee a box resists a directed jet, which pushes water at pressure into seams a static soak does not. If the enclosure faces both spray and possible immersion, specify both (IP66/IP67), not just the higher-looking number.
The rating is a system property, not a shell property
This is where box builds pass or fail: an IP rating applies to the finished, closed enclosure with everything installed — not to the empty shell. A rated result depends on every opening being sealed to the same level:
- The lid/cover gasket — a continuous, correctly compressed seal, not a gap at the corners.
- Cable entries — rated cable glands or sealed connectors; an unsealed hole is the most common leak path and it defeats the whole rating.
- Connectors and displays — panel-mount connectors and any window or membrane must carry their own matching IP rating and be installed with their seals.
- Seams and fasteners — screw bosses, seams, and vents (a breathable vent may be needed to prevent pressure differences that pull water past seals, though it passes almost no heat — see thermal management in enclosures for how to cool a sealed box).
Because it is a system property, integrating the electronics, seals, and interfaces into a sealed assembly is part of the build, not an afterthought — see our enclosure integration capability. The enclosure material and process also shape how sealing is achieved; the sheet metal vs injection molding enclosure comparison covers how the housing choice affects gasket channels and glands.
For the route behind a sealed entry, cable management and wire routing in enclosures explains how to define strain relief, bend clearance and fixing points alongside the gland.
How the rating is verified
An IP rating is earned by testing to IEC 60529, not by claiming it. The first digit is verified with defined probes and dust-chamber tests; the second with the specific water test for that level (spray nozzle, jet nozzle, or immersion). For production, confirm whether the rating is verified on the qualified design (type test) and whether any per-unit check applies to your program. A rating on a datasheet for a component enclosure is a starting point; the finished box build with your cable entries and interfaces is what actually has to hold.
What to specify on your drawing
- The target IP rating, and both digits explicitly (or IPX_ if only one axis matters), plus IP66/IP67 if both jet and immersion protection are required.
- The sealed interfaces — which cable entries, connectors, and displays must meet the rating, and the gland or connector series if you have a preference.
- The environment — outdoor, washdown, submersion, or steam clean — so the supplier can confirm the rating suits the real threat rather than a number on a page.
- Verification — whether IEC 60529 type-test evidence is required, and any per-unit seal or leak check.
An IP rating is a precise, testable requirement, not a toughness adjective. State both digits, seal every opening to that level, and confirm the finished box — not the bare shell — is what was tested. For help matching a rating to your environment and sealing the interfaces, our enclosure integration team reviews the seals, glands, and connector choices before the build.
