IP66 vs IP49K
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP66 and IP49K are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 6 vs 4) and liquid protection (level 6 vs 9K). IP66 is rated for dust-tight and powerful water jets (12.5 mm nozzle), while IP49K provides > 1 mm — small wires and high-pressure, high-temp water jets.
IP66 is dust-tight and resists powerful water jets (12.5 mm nozzle, 100 kPa). A robust outdoor rating for equipment exposed to heavy rain, storms, or directed high-pressure hosing (but not high-pressure washdown).
Built to withstand protection against solid objects larger than 1.0 mm and resistance to high-pressure (8–10 MPa), high-temperature (80 °C) water jets. Classified as IEC 60529 ingress protection code IP49K, it pairs solid level 4 with liquid level 9K.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP66
6 — Dust-Tight
IP49K
4 — > 1 mm — Small Wires
Liquid protection (second digit)
IP66
6 — Powerful Water Jets (12.5 mm nozzle)
IP49K
9 — High-Pressure, High-Temp Water Jets
Dust-tight
IP66
Yes
IP49K
No
Water-jet resistant
IP66
Yes
IP49K
Yes
Submersible
IP66
No
IP49K
Yes
Outdoor suitable
IP66
Yes
IP49K
Yes
The exact difference (IP66 vs IP49K)
Solid protection
IP66
Level 6 — Dust-Tight
IP49K
Level 4 — > 1 mm — Small Wires
IP66 provides "Dust-Tight" (level 6), while IP49K provides "> 1 mm — Small Wires" (level 4). IP66 is 2 levels higher.
Liquid protection
IP66
Level 6 — Powerful Water Jets (12.5 mm nozzle)
IP49K
Level 9 — High-Pressure, High-Temp Water Jets
IP66 handles 100 kPa (Powerful Water Jets (12.5 mm nozzle)), while IP49K handles 8–10 MPa (High-Pressure, High-Temp Water Jets). IP49K provides 3 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP49K offers higher overall protection than IP66. Choose IP49K for harsher environments; IP66 may suffice for milder conditions and can be more cost-effective.