This article is the overview page on IP protection classes: it explains what the digits mean, provides the full table per DIN EN 60529 and ISO 20653, and links at the end to the detailed article on IP57. Anyone looking for that level of detail on a specific rating finds it there rather than duplicated here.
IP stands for "International Protection". In English-speaking regions, "Ingress Protection" is often used instead. Both terms refer to the same series of standards.
The two digits after the IP abbreviation describe protection against contact, foreign objects, dust, and water. The combinations are defined in the standard DIN EN 60529 and, specifically for road vehicles, in ISO 20653. Both standards define the same basic protection levels but differ in details such as test setups and individual suffixes, for example the K suffix in ISO 20653 for increased pressure.
| First Digit | Meaning | ||
|---|---|---|---|
| ISO 20653 | DIN EN 60529 | Protection against contact | Protection against foreign objects |
| No protection | No protection | ||
| 1 | 1 | Protected against large-area contact (e.g. back of the hand) | Protected against large solid foreign objects (diameter ≥ 50 mm) |
| 2 | 2 | Protected against contact with a finger | Protected against medium-sized solid foreign objects (diameter ≥ 12 mm) |
| 3 | 3 | Protected against contact with tools and wires (diameter ≥ 2.5 mm) | Protected against small solid foreign objects (diameter ≥ 2.5 mm) |
| 4 | 4 | Protected against contact with tools and wires (diameter ≥ 1 mm) | Protected against granular solid foreign objects (diameter ≥ 1 mm) |
| 5K | 5 | Complete protection against contact | Protected against dust in harmful quantities (dust-protected) |
| 6K | 6 | Complete protection against contact | Complete protection against dust ingress (dust-tight) |
| Second Digit | Meaning | ||
|---|---|---|---|
| ISO 20653 | DIN EN 60529 | Protection against water | |
| No protection | |||
| 1 | 1 | Protected against vertically falling drops of water | |
| 2 | 2 | Protected against drops of water falling at an angle (up to 15°) | |
| 3 | 3 | Protected against spraying water up to 60° from vertical | |
| 4 | 4 | Protected against splashing water from all directions | |
| 4K | Protected against splashing water from all directions with increased pressure | ||
| 5 | 5 | Protected against water jets (nozzle) from any angle | |
| 6 | 6 | Protected against powerful water jets | |
| 6K | Protected against powerful water jets under increased pressure | ||
| 7 | 7 | Protected against temporary immersion | |
| 8 | 8 | Protected against continuous immersion | |
| 9 | Protected against water from high-pressure/steam-jet cleaning in agriculture | ||
| 9K | Protected against water from high-pressure/steam-jet cleaning for road vehicles | ||
When one of the two digits is replaced with an X, as in IP5X, it means no test was performed for that position, or no value is stated, not that there is no protection at all. IP5X therefore only says something about dust protection and makes no statement about water protection.
Per their respective datasheets, the Durabook tablets R8, R11, R11L and U11I, along with the Durabook Z14I among the laptops, reach IP66. The Durabook S15 and the Durabook S14I optionally reach IP53. The older Durabook S15AB sits at IP5X. These differences are not arbitrary: they are directly tied to housing design, weight, and operating temperature range, as shown in the direct device comparison in the article Rugged Laptops.
IP53 reliably protects against dust and spraying water up to 60 degrees from vertical, but not against powerful water jets or immersion. IP66, by contrast, means complete dust-tightness and protection against powerful water jets from any angle. For construction sites with occasional rain, IP53 is usually sufficient; for pressure washing or continuous exposure to splashing water, IP66 is the safer choice.
DIN EN 60529 is the general standard for electrical equipment and applies across industries, from IT devices to household electronics to industrial systems. ISO 20653 was developed specifically for the automotive sector and accounts for test conditions typical in vehicle environments, such as the higher pressures used in car washes. For rugged laptops and tablets, which are primarily used outside vehicles, DIN EN 60529 is usually the more relevant reference standard, even though many manufacturers cite both in their datasheets to make the test methodology transparent.
The IP rating and MIL-STD-810 drop protection are frequently confused, but they are two independent tests. The IP rating describes only protection against dust and water, not resistance to mechanical shock or drops. A device with a high IP rating can still be vulnerable to drops if it has not also been tested to MIL-STD-810. What the MIL-STD-810 test actually shows is explained in the article Drop Protection per MIL-STD-810: Test Setup and Significance.
This overview covers the fundamentals. Anyone wanting to know exactly what a specific rating means in detail, which test setups apply, and where its limits lie, finds that depth in a dedicated article. Robustbook currently publishes this level of detail in English for one rating:
Further detailed articles, on IP54, IP55, IP65 and IP67, are currently only available in German; the German overview at IP-Schutzklassen links to all five.
Anyone unsure which rating is sufficient for their use case should first realistically assess actual exposure to dust and water: occasional rain in the field calls for a different class than continuous use at a car wash or in a production hall with fine dust. An overview of which device carries which rating is also available in the Laptop Comparison Table and the Tablet Comparison Table. When in doubt, the higher rating is worth choosing, since sealing cannot be upgraded later during operation.
Robustbook offers laptops and tablets with different IP ratings, from IP53 on the Durabook S15 to IP66 on the tablets and the Durabook Z14I. For an assessment of which rating is sufficient for your use case, the team is available via the contact page.