IP ratings appear on every actuator datasheet, and they are the most misunderstood two characters in industrial procurement. Buyers treat them as a simple hierarchy — '68 is better than 66, so buy 68' — and then pay for protection they don't need, or skip protection they do.
This guide decodes the IEC 60529 standard in plain language and tells you which rating matches which real-world installation.
How to read the two digits
IP stands for Ingress Protection. The first digit covers solids, the second covers liquids.
- First digit (solids): 5 = dust-protected (limited ingress, no harm); 6 = dust-tight (no ingress at all). For actuators in dusty industry, 6 is the honest choice.
- Second digit (liquids): this is where the confusion lives — the digits are NOT a simple hierarchy, they describe different test methods: dripping (3), spraying (5), powerful jets (6), temporary immersion (7), continuous immersion (8), high-pressure high-temperature spray (9K).
- An IP68 unit is tested for immersion — it is not automatically tested for powerful jets. IP66 and IP68 test different things.
The practical differences that matter
Match the test to the threat your installation actually presents.
- IP66: powerful water jets from any direction — the honest rating for outdoor installations and washdown-adjacent areas. The workhorse rating of industry.
- IP67: temporary immersion (30 minutes at 1 m). Good for pits that flood briefly — check the stated depth and duration.
- IP68: continuous immersion under conditions agreed with the manufacturer — the rating for permanently submerged or repeatedly flooded installations. Always ask depth and duration.
- IP69K: close-range high-pressure, high-temperature spray (the food-industry washdown benchmark). A distinct test, not 'better than 68'.
Common mistakes the rating system creates
Three misunderstandings cost buyers real money every year.
- 'IP68 beats IP66, so it also handles jets.' Not necessarily — immersion and jets are different tests. A unit can pass 8 and fail 6. The honest spec sheet states both (e.g., IP66/IP68).
- 'The gland is part of the rating.' The enclosure is only as sealed as its weakest entry. A perfect IP68 housing with a push-fit gland is an IP4x housing.
- 'IP rating means corrosion protection.' It does not — corrosion is covered by coating classes and materials. Salt fog requires C5-M-class protection regardless of IP code.
Which rating for which installation.
How SJMC rates its actuators
JVX units are rated IP66 as standard with IP68 configurations available for flooded installations — and we state exactly what the immersion conditions are. Glands are double-sealed as standard, because we learned early that the gland is where ratings die.
- JVX-01 Quarter-turn — IP66 standard, IP68 configuration for pits and flood-prone installations.
- JVX-05 Compact economy — IP66 protection at the economy price point for indoor and sheltered duty.
- Double-sealed glands — Standard on all JVX units — the detail that keeps the rating honest in the field.
Frequently asked questions
Is IP68 always better than IP66?
No — they test different threats. IP68 covers immersion; IP66 covers powerful jets. Many serious applications specify both (e.g., IP66/IP68) because jet and immersion tests differ.
What IP rating do I need outdoors?
IP66 is the honest workhorse rating for outdoor actuators exposed to rain and occasional hose cleaning. Go higher only for immersion or food-washdown zones.
Why did my 'IP67' actuator leak at the cable entry?
Almost certainly the gland. The overall rating is defined by the weakest sealing point, and generic glands are the usual culprit. Specify matched, double-sealed glands.