Complete Guide to IP Ratings: Chart, Meanings, and How to Choose

Complete Guide to IP Ratings: Chart, Meanings, and How to Choose

IP ratings tell you exactly how well an enclosure protects against dust and water — no vague marketing terms like "waterproof" or "dust-resistant." Whether you’re selecting a linear actuator for an outdoor installation, choosing electronics for a marine environment, or specifying equipment for a food-processing washdown, understanding IP ratings is essential for making the right choice.

This guide covers the full IP rating chart, explains what every digit and letter means, compares IP65 vs IP66 vs IP67 vs IP68, shows NEMA equivalents, and gives specific recommendations for actuator applications.

What Is an IP Rating?

IP stands for Ingress Protection. The IP rating is an international standard defined by IEC 60529 (also BS EN 60529:1992 in the UK and European IEC 60509:1989) that classifies the degree of protection an enclosure provides against two things: solid objects (dust, debris, fingers, tools) and liquids (drips, spray, jets, full immersion).

The IP rating uses two digits after the letters “IP”:

• First digit (0–6) — protection against solid particles, from no protection (0) to completely dust-tight (6)
• Second digit (0–9K) — protection against liquid ingress, from no protection (0) to high-pressure, high-temperature jet spray (9K)

For example, IP67 means: complete dust protection (6) + temporary immersion up to 1 meter for 30 minutes (7).

How do you get an IP rating? Manufacturers cannot self-assign IP ratings. An independent, certified testing laboratory must carry out standardized tests and verify the results. This is what makes IP ratings reliable — unlike vague marketing terms like “waterproof” or “weatherproof,” an IP rating tells you the exact conditions the product was tested against.

Why do IP ratings matter? Choosing the wrong IP rating can mean equipment failure, corrosion, electrical shorts, or even safety hazards. For linear actuators, understanding IP ratings is especially important because actuators are used in everything from camper van roof lifts to TV lifts, solar tracker systems, marine hatches, and industrial washdown environments — each requiring different levels of protection.

The Complete IP Rating Chart

The table below shows every possible first digit (solid protection) and second digit (liquid protection) and what each means:

First Digit	Solid Particle Protection	Second Digit	Liquid Ingress Protection
0	No protection against contact or solid objects	0	No protection against liquid
1	Protection from large body parts (e.g., back of hand) and solids larger than 50 mm	1	Protection against vertical dripping water (mounted upright, rotated at 1 rpm)
2	Protection from fingers or objects up to 80 mm long and 12 mm diameter	2	Protection against vertical dripping water when tilted up to 15° from normal position
3	Protection from tools, wires, or objects larger than 2.5 mm diameter	3	Protection against water spray at any angle up to 60° from vertical
4	Protection against objects larger than 1 mm (wires, screws, large insects)	4	Protection against water splashing from any direction
5	Dust-protected — partial protection, dust may enter but not enough to interfere with operation	5	Protection against low-pressure water jets (6.3 mm nozzle) from any direction
6	Dust-tight — complete protection, no dust ingress	6	Protection against powerful water jets (12.5 mm nozzle) from any direction
		6K	Protection against powerful water jets with increased pressure (6.3 mm nozzle)
		7	Protection against temporary immersion up to 1 m depth (typically 30 minutes)
		8	Protection against continuous immersion beyond 1 m depth (manufacturer specifies conditions)
		9K	Protection against high-pressure (1160–1450 psi), high-temperature (80°C) close-range water jets
X	Not tested for solid protection — treat as 0 (e.g., IPX4 = splash-proof only)	X	Not tested for liquid protection — treat as 0 (e.g., IP5X = dust-protected only)

Additional Letters in IP Ratings

Some IP ratings include a letter suffix that provides additional information about the test conditions or protection type:

Letter	Meaning	What It Tells You
A	Back of hand	Protected against accidental contact with back of hand
B	Finger	Protected against finger contact with hazardous parts
C	Tool	Protected against tool access to hazardous parts
D	Wire	Protected against wire access to hazardous parts
F	Oil resistant	Seals resist oil absorption and swelling (important for rubber seals)
H	High voltage device	Rated for voltage surges over 50 kV
M	Motion during water test	Device was operating/moving during the water test — critical for actuators
S	Standing still during water test	Device was stationary during the water test
W	Weather conditions	Tested for additional weather protection (rain, wind-blown debris)

The M suffix is especially important for linear actuators. A standard IP67 rating means the actuator was tested while stationary. When an actuator extends or retracts, the moving shaft can draw water into the housing through a pumping action, potentially damaging the motor. An IP67M rating means the actuator was tested while in motion during water exposure — a much more rigorous and realistic test for actuators that must operate in wet conditions.

Understanding IP Digits: What the Numbers Mean in Practice

Knowing the chart is one thing — understanding which IP rating you actually need depends on the environment. Here is what each protection level means in practical terms:

First Digit: Solid Protection in Practice

• IP0X – IP2X: Basic protection from fingers and large objects. Suitable for indoor electrical panels and junction boxes where dust is not a concern.
• IP3X – IP4X: Protected from tools and small objects (wires, screws). Suitable for indoor industrial environments with limited debris.
• IP5X: Dust-protected — some dust may enter, but not enough to affect operation. Suitable for light-duty outdoor and indoor factory use.
• IP6X: Completely dust-tight. Required for outdoor installations, construction sites, woodworking shops, mines, and anywhere fine particles are present. All FIRGELLI actuators rated IP65 and above are dust-tight (6).

Second Digit: Liquid Protection in Practice

• IPX1 – IPX2: Protection from dripping water only. Indoor use where condensation or minor drips may occur.
• IPX3 – IPX4: Water-resistant. Protected from rain and splashing. Suitable for sheltered outdoor installations and bathrooms.
• IPX5: Protected from low-pressure water jets (garden hose equivalent). Suitable for general outdoor use and light washdown environments.
• IPX6: Protected from powerful water jets (power washer). Required for marine environments, heavy rain exposure, and industrial washdown.
• IPX7: Survives temporary immersion up to 1 m for 30 minutes. Suitable for equipment in flood-prone areas or accidental submersion.
• IPX8: Survives continuous immersion beyond 1 m (manufacturer specifies depth and duration). Required for permanently submerged equipment.
• IPX9K: Survives high-pressure, high-temperature close-range jets. Required for food processing, pharmaceutical, and heavy industrial washdown.

IP65 vs IP66 vs IP67 vs IP68: Which Do You Need?

These four ratings are the most commonly compared because they all share complete dust protection (first digit 6) but differ in liquid protection. Here is a practical comparison:

Important: IP ratings are not cumulative. An IP67-rated device has been tested for immersion but not necessarily for high-pressure jets (IP66). If you see a dual rating like IP55/IP57, it means the device passed both the jet test (5) and the immersion test (7) but did not pass the powerful jet test (6). A single rating like IP67 implies all lower tests in that category were also passed.

IP Ratings for Linear Actuators

A linear actuator converts electrical energy into linear (push/pull) motion. Because actuators are used in everything from indoor furniture lifts to outdoor marine hatches, the required IP rating varies widely by application.

Actuator IP Rating by Environment

The M Suffix: Why It Matters for Actuators

Standard IP water tests are performed with the device stationary. But actuators move — and when the shaft extends or retracts, it can create a pumping action that draws water into the housing. This means a standard IP67 actuator may not be waterproof while actually operating.

An IP67M rating means the actuator was tested while in motion during the water test. If your actuator must operate in wet conditions (not just survive being wet while off), look specifically for the M suffix. FIRGELLI’s Tubular actuator series offers the highest water protection in the product line.

Choosing an Actuator by IP Rating

FIRGELLI offers actuators across a range of IP ratings to match your application:

• All Linear Actuators — browse the full range and filter by IP rating
• Bullet 50 Cal Series — compact, high-force actuators for confined spaces
• Super Duty Series — heavy-duty actuators for demanding applications
• Feedback Rod Actuators — position feedback for precise control

NEMA Ratings and IP Equivalents

In North America, electrical enclosures are often rated using the NEMA 250 standard instead of (or alongside) IP ratings. NEMA stands for National Electrical Manufacturers Association. NEMA ratings include additional factors that IP ratings do not cover, such as corrosion resistance, gasket aging, construction practices, and suitability for hazardous atmospheres.

Because the standards use different test methods, NEMA-to-IP conversions are approximate — but here are the most commonly referenced equivalents:

IK Ratings: Mechanical Impact Protection

The IK rating is a separate standard (IEC 62262) that measures protection against mechanical impact. It used to be included within the IP system but is now a standalone code. If you see an IK rating alongside an IP rating, here is what it means:

How IP Ratings Are Tested

Understanding the testing methods helps clarify what each rating actually protects against and where the boundaries are.

Dust Testing (IP5X and IP6X)

Dust tests are conducted in sealed chambers where a dust-air mixture (typically talcum powder) is circulated around the device. Conditions can range from ambient temperature to 100°C at elevated pressure. The chamber typically has a small opening (~80 mm) for cables and hoses. After the test period, the device is inspected to determine whether dust has penetrated the enclosure.

• IP5X (dust-protected): Some dust may enter, but not enough to interfere with operation
• IP6X (dust-tight): No dust ingress whatsoever after the full test duration

Water Resistance Testing (IPX1 – IPX4)

These tests verify protection against dripping water, rain, and splashing:

• IPX1 / IPX2: Dripping water from overhead nozzles (~0.4 mm diameter). IPX2 adds a 15° tilt to the device. This simulates condensation and minor indoor drips.
• IPX3 / IPX4: Water sprayed from oscillating spray heads at various angles. IPX4 allows spray from all directions (no shielding). This simulates rain and splashing.

Water Jet Testing (IPX5 – IPX6K)

• IPX5: Water projected from a 6.3 mm nozzle at 12.5 liters/min from 3 meters distance, from any direction, for at least 3 minutes. Equivalent to a garden hose.
• IPX6: Water projected from a 12.5 mm nozzle at 100 liters/min from 3 meters distance. Equivalent to a power washer.
• IPX6K: Same as IPX6 but at increased pressure from a 6.3 mm nozzle. A more demanding jet test.

Immersion Testing (IPX7 – IPX8)

• IPX7: Device immersed in up to 1 meter of water for 30 minutes. Any water ingress must not cause harmful effects. This tests against accidental submersion — dropping a phone in a sink, or flood water reaching equipment temporarily.
• IPX8: Device immersed deeper than 1 meter for a duration specified by the manufacturer. Equipment designed for permanent underwater use must be sealed airtight, but the test verifies that any minor seepage does not cause damage.

High-Pressure / High-Temperature Testing (IPX9K)

The IPX9K test is the most rigorous water test. The device is mounted on a turntable rotating at 5 rpm while high-pressure (1160–1450 psi), high-temperature (80°C / 176°F) water is sprayed from 10–15 cm distance. Only devices that pass this test can be confidently used in food processing, pharmaceutical manufacturing, and other aggressive washdown environments.

Summary: How to Choose the Right IP Rating

Choosing the right IP rating comes down to understanding your environment and what threats your equipment faces. Here is a decision framework:

1. Identify the dust exposure. Indoor with minimal dust? IP2X–IP4X is fine. Outdoor, construction, woodworking, or manufacturing? You need IP5X or IP6X (dust-tight).
2. Identify the water exposure. Drips and condensation? IPX1–IPX2. Rain and splash? IPX3–IPX4. Hose spray? IPX5–IPX6. Submersion risk? IPX7–IPX8. High-pressure washdown? IPX9K.
3. Consider motion (for actuators). If the actuator must operate while wet, require the M suffix (e.g., IP67M).
4. Don’t over-specify. A higher IP rating increases cost and may limit other product features. An indoor TV lift does not need IP67 — IP40 is sufficient. Match the rating to the actual environment, not worst-case imagination.
5. Check for dual ratings. If you see IP55/IP57, the device passed jet (5) and immersion (7) tests but not the powerful jet (6) test. Understand what each number means before assuming complete protection.

For help selecting the right actuator for your application, visit our full linear actuator range or use our Actuator Sizing Calculator to find the right fit for your project.

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• Polarity Reversal Guide — how to reverse actuator direction with switches, relays, and H-bridges
• Types of Linkages Guide — mechanical linkage types used with actuators
• Mastering Mechanical Advantage — levers, pulleys, gears, and hydraulics explained
• Full Calculator Suite — all FIRGELLI engineering calculators in one place
• Camper Van Pop-Top Roof Build — IP-rated actuators for outdoor van conversions
• FIRGELLI Main Website — full product catalog and technical specifications