IP18 vs IP39K
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP18 and IP39K are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 1 vs 3) and liquid protection (level 8 vs 9K). IP18 is rated for > 50 mm — back of hand and continuous immersion (manufacturer-specified), while IP39K provides > 2.5 mm — tool / wire and high-pressure, high-temp water jets.
The IP18 classification guarantees protection against solid objects larger than 50 mm and protection against the effects of continuous immersion in water under conditions specified by the manufacturer.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 1 with second-digit (liquid) level 8.
IP39K is an ingress protection code that ensures protection against solid objects larger than 2.5 mm and resistance to high-pressure (8–10 MPa), high-temperature (80 °C) water jets. It is an IEC 60529 ingress protection code combining first-digit (solid) level 3 with second-digit (liquid) level 9K.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP18
1 — > 50 mm — Back of Hand
IP39K
3 — > 2.5 mm — Tool / Wire
Liquid protection (second digit)
IP18
8 — Continuous Immersion (manufacturer-specified)
IP39K
9 — High-Pressure, High-Temp Water Jets
Dust-tight
IP18
No
IP39K
No
Water-jet resistant
IP18
Yes
IP39K
Yes
Submersible
IP18
Yes
IP39K
Yes
Outdoor suitable
IP18
Yes
IP39K
Yes
The exact difference (IP18 vs IP39K)
Solid protection
IP18
Level 1 — > 50 mm — Back of Hand
IP39K
Level 3 — > 2.5 mm — Tool / Wire
IP18 provides "> 50 mm — Back of Hand" (level 1), while IP39K provides "> 2.5 mm — Tool / Wire" (level 3). IP39K is 2 levels higher.
Liquid protection
IP18
Level 8 — Continuous Immersion (manufacturer-specified)
IP39K
Level 9 — High-Pressure, High-Temp Water Jets
IP18 handles Specified by manufacturer (Continuous Immersion (manufacturer-specified)), while IP39K handles 8–10 MPa (High-Pressure, High-Temp Water Jets). IP39K provides 1 level more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP39K offers higher overall protection than IP18. Choose IP39K for harsher environments; IP18 may suffice for milder conditions and can be more cost-effective.