IP33 vs IP66
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP33 and IP66 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 3 vs 6) and liquid protection (level 3 vs 6). IP33 is rated for > 2.5 mm — tool / wire and spraying water (up to 60°), while IP66 provides dust-tight and powerful water jets (12.5 mm nozzle).
IP33 protects against tools and 2.5 mm objects plus spraying water up to 60° from vertical. A practical rating for indoor equipment subject to light spray or for sheltered outdoor fixtures.
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).
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP33
3 — > 2.5 mm — Tool / Wire
IP66
6 — Dust-Tight
Liquid protection (second digit)
IP33
3 — Spraying Water (up to 60°)
IP66
6 — Powerful Water Jets (12.5 mm nozzle)
Dust-tight
IP33
No
IP66
Yes
Water-jet resistant
IP33
No
IP66
Yes
Submersible
IP33
No
IP66
No
Outdoor suitable
IP33
No
IP66
Yes
The exact difference (IP33 vs IP66)
Solid protection
IP33
Level 3 — > 2.5 mm — Tool / Wire
IP66
Level 6 — Dust-Tight
IP33 provides "> 2.5 mm — Tool / Wire" (level 3), while IP66 provides "Dust-Tight" (level 6). IP66 is 3 levels higher.
Liquid protection
IP33
Level 3 — Spraying Water (up to 60°)
IP66
Level 6 — Powerful Water Jets (12.5 mm nozzle)
IP33 handles 80 kPa (tube) / 50 kPa (nozzle) (Spraying Water (up to 60°)), while IP66 handles 100 kPa (Powerful Water Jets (12.5 mm nozzle)). IP66 provides 3 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP66 offers higher overall protection than IP33. Choose IP66 for harsher environments; IP33 may suffice for milder conditions and can be more cost-effective.